Interior Doors Calculator

How big should my door rough openings be? This free interior doors calculator gives DIYers and contractors a per-door schedule for the whole house — rough opening width and height, hinge count and size, lockset function and grade, specialty hardware (pocket frame, barn track, bifold kit, bypass kit, flush bolts, astragals, Dutch bolts), and the casing linear feet that feed the trim calculator — across 8 door types in one screen.

Pocket and barn doors are where rough-opening math goes sideways. Pocket frames vary by brand (Johnson 1500 = 2 × door + 1 in.; Eclisse Classic = 2 × door + 2 in.; Cavity Sliders TSC = 2 × door + 1-1/4 in.) — the calculator emits the conservative Johnson value with a brand-verification note. Barn doors size to opening + 4–6 in. with a track ≥ 2× slab width, rounded up to stock lengths (72, 78, 84, 96, 120, 144 in.).

Built on ICC IRC 2021 (R311.2 egress, R302.5.1 garage-to-dwelling, R308.4 safety glazing, R310 EERO), 2010 ADA Standards (404 clear width, 309 operable parts), ANSI/BHMA A156.1 / A156.2 / A156.13 / A156.18 (hinges, locksets, finishes, prep), NFPA 80 (fire-rated assemblies), and manufacturer technical data from Masonite, JELD-WEN, Reeb, L.E. Johnson, Eclisse, Real Sliding Hardware, Schlage, Hager, and Stanley.

View material estimation guides →

How a door take-off actually works

Three details decide a door order more than the room does. These engineering-style diagrams show why the rough opening is bigger than the door, how many hinges a door needs and where the 5/10 rule puts them, and why a barn, bypass, or pocket door’s slab and track are not the same width as the opening.

The rough-opening detail is why the calculator frames a bigger hole than the door. The rough opening adds width and height for the jamb and a shim gap that lets the frame be set plumb and level, so you order the door by its nominal size but frame to the larger opening. Frame to the door size and there is no room to square the jamb.

A framed wall opening with a pre-hung door nested inside it, showing why the rough opening is bigger than the door. A 30-inch-wide by 80-inch-tall door needs a rough opening framed 32 inches wide and 82½ inches tall: the extra 1 inch on each side and 2½ inches at the head leave room for the jamb plus a shim gap so the finished frame can be set plumb and level. The rough opening is measured between the trimmer (jack) studs and the underside of the header, not to the door. So the rule for a standard pre-hung or slab is rough opening width equals door width plus 2 inches, and rough opening height equals door height plus 2½ inches. Order the door by its nominal size; frame the wall to the larger rough opening. — The hole in the wall is bigger than the door. A standard pre-hung / slab needs a rough opening = door width + 2″ wide × door height + 2½″ tall — the extra inch each side and 2½″ at the head are the jamb plus shim gap that lets the frame be set plumb and level. Order the door by nominal size; frame to the RO.Source: Pre-hung rough-opening rule (door + 2″ W × 2½″ H); ANSI/BHMA door prepSee the Interior door rough opening diagram →(opens in a new tab)

The hinge-schedule diagram is why hinge count follows door height and weight. Taller doors take more hinges, placed by the five-and-ten rule, and heavy or fire-rated leaves need ball-bearing hinges or an extra one. The calculator counts hinges from the door, not a flat number, because an under-hinged heavy door sags.

A door elevation showing how many hinges a passage door needs and where they go. Hinge count is set by door height: up to 60 inches takes 2 hinges, 61 to 90 inches takes 3, and 91 to 120 inches takes 4. A standard 80-inch door therefore uses 3 hinges. Placement follows the residential 5/10 rule: the top hinge is 5 inches from the top of the door, the bottom hinge is 10 inches from the bottom, and the middle hinge is centered between them. Heavy doors get ball-bearing hinges — required for solid-wood, glass, or fire-rated doors and for any leaf over about 50 pounds — and an extra hinge is added when a door is over 200 pounds or wider than 48 inches. The knob or lever centerline sits at 36 inches above the floor, within the ADA 34-to-48-inch range. — Hinge count is set by height: ≤60″ = 2, 61–90″ = 3, 91–120″ = 4 — so a standard 80″ door takes 3. Placement is the 5/10 rule: top hinge 5″ from the top, bottom hinge 10″ from the bottom, middle centered. Go ball-bearing for solid-wood / glass / fire-rated or any leaf over ~50 lb; add a hinge over 200 lb or 48″ wide.Source: ANSI/BHMA A156.1 (hinge count by height); 5/10 residential placement; ADA 404.2.7 (34–48″ AFF)See the Interior door hinge schedule →(opens in a new tab)

The door-type comparison explains why the opening math changes with the door type. A swing door fills its opening, a barn door overhangs it and needs double the track, a bypass splits into two panels, and a pocket door needs roughly double the width because the slab hides in the wall. The type is why two doors of the same width need different framing.

Four small elevations comparing how a door’s slab or track relates to the finished opening, because the slab width is not the same as the opening width for sliding doors. A pre-hung swing door fills its opening: the rough opening equals the door plus 2 inches. A barn door must be wider than the opening — about 4 to 6 inches wider so it overlaps and covers the gap on each side — and its wall-mounted track has to be at least twice the slab width so the door can slide fully clear. A bypass closet uses two doors on parallel tracks, each about half the opening plus a half inch of overlap where they meet. A pocket door slides into a hollow pocket built inside the wall, so its rough opening is roughly twice the door width plus 1 inch to hold both the doorway and the pocket. This is why the calculator asks for the opening as well as the door. — The slab is not the opening. A swing door fills it (RO = door + 2″). A barn door is 4–6″ wider than the opening so it overlaps the gap, and its track runs ≥ 2× the slab width. A bypass uses two doors, each ≈ opening ÷ 2 + ½″ overlap. A pocket door needs RO ≈ 2 × door + 1″ because the slab hides inside the wall.Source: Barn / bypass / pocket sizing (L.E. Johnson 1500, Cavity Sliders, Eclisse); pre-hung RO ruleSee the Door slab and track size vs. the opening diagram →(opens in a new tab)

Calculation Formulas

Pre-Hung Swing Rough Opening

RO_w = door_w + 2 in.; RO_h = door_h + 2-1/2 in.

Industry-universal across EZ-Hang, Builders Surplus, MMI Door, Masonite, and JELD-WEN install guides. The 2 in. width allowance covers ~3/4 in. jamb stock each side plus ~1/4 in. of total shim. The 2-1/2 in. height covers head jamb plus floor-to-jamb gap for finished flooring.

Example:

30 × 80 in. pre-hung → RO 32 in. × 82-1/2 in. (the values stamped on Masonite and JELD-WEN labels).

Double / French Pair Rough Opening

RO_w = (2 × door_w) + 2 in.; RO_h = door_h + 2-1/2 in.

MMI Door / JELD-WEN technical: where an astragal sits between leaves a small additional allowance (~1/2 in.) may be required — defer to active hardware schedule. Default is 2 in.

Example:

Two 30 in. leaves at 80 in. → RO 62 in. × 82-1/2 in.

Pocket Door Rough Opening (Conservative)

RO_w = (2 × door_w) + 1 in.; RO_h = door_h + 4-1/2 in.

Johnson 1500 series — the most-spec'd residential pocket frame. Eclisse Classic uses 2W + 2 in.; Cavity Sliders TSC uses 2W + 1-1/4 in. The calculator emits the conservative Johnson value and a brand-verification note. Height accommodates the track header.

Example:

30 × 80 in. pocket → RO 61 in. × 84-1/2 in.; 36 × 96 in. pocket → RO 73 in. × 100-1/2 in.

Barn Door Slab and Track

slab_w = opening_w + 4–6 in.; slab_h = opening_h + 1 in.; track ≥ 2 × slab_w

Real Sliding Hardware, Rustica, and Goldberg Brothers convention. 6 in. of total side overlap (3 in. each) is the privacy default for bedrooms and bathrooms; 4 in. is acceptable for closets and pantries. Track length must be at least 2× slab width so the door fully clears the opening — round up to the next stock length (72 / 78 / 84 / 96 / 120 / 144 in.).

Example:

36 in. opening, 80 in. height → slab 42 × 81 in. with 84 in. track stock.

Bypass 2-Door Sizing

each_door_w = (opening_w / 2) + 1/2 in.; track_length = opening_w

Industry overlap default = 1 in. total. Each door is 1/2 in. wider than half the opening so the meeting stiles overlap when closed and there is no light gap.

Example:

72 in. closet → 2 × 36-1/2 in. doors on a 72 in. track.

Bifold Configuration by Opening

≤ 36 in. = 1 pair (2 panels); ≤ 72 in. = double pair (4 panels); > 72 in. = custom triple pair

Bifold panels are sold per the nominal opening — slab is undersized 1/2 in. so the as-supplied panels fit a true nominal RO. RO width equals the nominal opening size.

Example:

60 in. linen closet → double pair (four 15 in. panels); 36 in. closet → 1 pair (two 18 in. panels).

Hinge Count by Door Height

≤ 60 in. → 2; ≤ 90 in. → 3; ≤ 120 in. → 4; +1 per additional 30 in.; +1 if > 200 lb or > 48 in. wide

ANSI/BHMA A156.1 application chart. 80 in. and 84 in. doors take 3 hinges (the residential default); 96 in. tall doors need 4. Doors heavier than 200 lb or wider than 48 in. add an extra hinge regardless of height.

Example:

Standard 80 in. residential door → 3 hinges. 96 in. tall door → 4 hinges. 96 in. solid wood at 48 in. wide → 5 hinges.

Hinge Size by Thickness × Width

1-3/8 in. ≤ 32 in. wide → 3-1/2 in. hinge; 1-3/8 in. ≤ 36 in. → 4 in.; 1-3/4 in. ≤ 36 in. → 4 in.; 1-3/4 in. ≤ 48 in. → 4-1/2 in.; > 48 in. → 5 in.

Hager / Stanley / Bommer published sizing chart. 3-1/2 × 3-1/2 in. with 1/4 in. or 5/8 in. radius corner is the residential default; 4 × 4 in. is used on 1-3/4 in. solid-core slabs and the standard fire-rated garage door.

Example:

30 × 80 × 1-3/8 in. bedroom door → three 3-1/2 in. hinges; 32 × 80 × 1-3/4 in. fire door → three 4 in. ball-bearing hinges.

Casing Linear Feet per Opening

LF_per_side = (2 × door_h + door_w) / 12; LF_total = sides_cased × LF_per_side × (1 + waste)

Both legs plus the head, divided by 12 to convert inches to feet. Pre-hungs and pairs are cased on both sides. Pocket doors get a full case on the strike side and a partial / split jamb on the pocket side (≈ 1.6× per side). Bifold / bypass / barn are typically cased one side. Slab in existing jamb has 0 LF demand.

Example:

30 × 80 in. door, 10% paint waste → per side 15.83 LF × 2 sides × 1.10 ≈ 34.8 LF (matches the industry "17 LF per cased side" rule).

Egress Clear-Width Check

egress_clear_w = nominal_w − (jamb_offset + hinge_offset + stop) ≈ nominal_w − 2 to 2-1/2 in.

IRC R311.2 requires 32 in. minimum clear width measured between the door face and the stop with the door open 90°. A 36 in. nominal door is required to net 32 in. clear because thickness, hinge offset, and stop reduce the dimension by ~2 to 2-1/2 in. The calculator flags any house where no specified door is 36 in. × 80 in. swing.

Example:

36 × 80 in. solid-core door on 4-9/16 in. jamb → ~33-1/2 in. clear, satisfies R311.2.

Garage-to-Dwelling Compliance

thickness ≥ 1-3/8 in. AND (solid wood OR solid-/honeycomb-core steel OR 20-min fire-rated) AND self-closer AND not into a sleeping room

IRC R302.5.1. Hollow core is prohibited. The door must self-close and self-latch. A door from the garage may NOT open into a sleeping room — re-route through a habitable space (mudroom, hall, stair landing). The calculator emits an explicit error for any non-compliant garage-adjacent door.

Example:

32 × 80 × 1-3/4 in. steel-clad 20-min fire-rated pre-hung with closer at the garage-to-mudroom boundary.

Standard Constants

Constant	Value	Description
Standard Slab Heights	80 in. (default), 84 in., 96 in.	80 in. (6'-8") is the residential default; 84 in. (7'-0") is a premium / taller-ceiling upgrade and is widely stocked; 96 in. (8'-0") is custom and requires 4 hinges per ANSI A156.1.
Standard Slab Thickness	1-3/8 in. (interior) / 1-3/4 in. (heavy)	1-3/8 in. is the residential interior default for hollow-core, solid-core, and most stile-and-rail slabs. 1-3/4 in. is used on solid wood, French / double pairs, garage-to-dwelling fire-rated, and exterior assemblies.
Common Stock Widths	24 / 28 / 30 / 32 / 36 in.	30 in. is the most common interior bedroom / bathroom width. 32 in. is preferred for accessibility and on basement / mudroom doors. 36 in. is required to net the 32 in. clear width for the IRC R311.2 egress door.
Std Jamb Depths	4-9/16 in. (2×4 + 1/2 in. drywall both sides) ; 6-9/16 in. (2×6 + 1/2 in. drywall)	Stock pre-hung jambs match the framed wall thickness. Where the wall does not match a stock depth, jamb extensions (rip strips) are field-applied. Calculator carries jamb depth as a separate input.
Hinge Convention	5/10 residential ; 7/11 commercial	5/10 — top hinge 5 in. from top of door, bottom hinge 10 in. from bottom, middle centered. The residential default per Reeb Learning Center, Masonite, JELD-WEN install guides. 7/11 is the commercial / heavy-slab convention.
Lockset Backset	2-3/8 in. residential / 2-3/4 in. commercial	Distance from the door edge to the centerline of the cross-bore. Most U.S. residential locksets ship with an adjustable latch that supports either backset. 2-3/8 in. is the standard for 1-3/8 in. doors; 2-3/4 in. is more common on 1-3/4 in. slabs.
Door Prep — Cross / Edge Bore	2-1/8 in. cross bore × 1 in. edge bore	ANSI A115.2 / ANSI/BHMA A156.115. Strike mortise 1-1/8 × 2-3/4 in. residential or 1-1/4 × 4-7/8 in. extended T-strike. Latch face plate mortise 1 × 2-1/4 × ~1/8 in. deep.
Hardware Mounting Height	Lever / knob centerline 36 in. AFF	U.S. residential convention. Falls inside ADA 404.2.7 (34 in.–48 in. AFF). ADA-compliant openings require lever handles, push-pull bars, or U-pulls — round knobs do not satisfy 'operable without tight grasping or twisting.' Operating force ≤ 5 lbf per ADA 309.4 / 404.2.9.
Lockset Grade (BHMA)	Grade 3 residential default	ANSI/BHMA A156.2 cycle test: Grade 3 = 200,000 cycles (residential). Grade 2 = 400,000 (premium residential / light commercial). Grade 1 = 800K–1M (heavy commercial, entry locks).
Pocket Frame Capacity	125 lb (Johnson 1500) / 200 lb (1500HD)	Standard 2×4 frames accept doors up to 1-3/8 in. thick at 125 lb. Heavy-duty 1500HD and 1500SC accept up to 200 lb. 1560 (2×6) accepts up to 3 in. thick doors and offers better lateral rigidity. The calculator picks std vs HD by thickness and construction.
Barn Track Capacity	200 lb residential / 400 lb HD / 600+ lb commercial	Per Real Sliding Hardware / National Hardware specs. 200-lb kits cover virtually every 1-3/8 in. wood slab up to 36 × 84 in.; 400-lb kits are required for solid wood, glass, or oversized slabs over ~80 lb. Track must lag into studs OR a continuous 1×4 / 1×6 backer along the entire length.

Note: All calculations include appropriate waste factors based on project complexity and material type. Results are estimates and should be verified by professionals before purchasing materials.

ICC International Residential Code (IRC) 2021(IRC 2021)

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The model code adopted (often with amendments) by most U.S. jurisdictions for one- and two-family dwellings. Defines the egress door, hallway widths, garage-to-dwelling boundary, and safety glazing for any glass at or near a door.

Key Requirements:

•R311.2 — At least one egress door per dwelling, side-hinged, ≥ 32 in. clear × ≥ 78 in. clear, openable from inside without key or special knowledge
•R311.6 — Hallway minimum width 36 in.
•R302.5.1 — Garage-to-dwelling door: solid wood ≥ 1-3/8 in., solid / honeycomb steel ≥ 1-3/8 in., or 20-minute fire-rated; self-closing and self-latching; cannot open into a sleeping room
•R308.4 — Safety glazing (tempered or laminated) required in all glass within doors and within a 24 in. arc of door edges below 60 in. AFF
•R310 — Emergency Escape and Rescue Opening for every basement and sleeping room — separate from and in addition to the room's interior door

Applies to:All one- and two-family dwellings and townhouses ≤ 3 stories built under IRC-adopting jurisdictions.

2010 ADA Standards for Accessible Design(28 CFR Part 36 / DOJ 2010 ADA)

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The U.S. Department of Justice accessibility standard. Not generally required in single-family detached residential, but referenced for accessory dwelling units, multi-family covered by the FHA, and any accessible-design project.

Key Requirements:

•404.2.3 — Door clear width: 32 in. minimum measured between face of door (open 90°) and stop
•404.2.7 — Operable parts of hardware: 34 in.–48 in. AFF; operable with one hand without tight grasping, pinching, or twisting
•404.2.8 — Closing speed: from 90° open ≥ 5 seconds to reach 12° from latch
•404.2.9 — Opening force: interior hinged non-fire ≤ 5 lbf
•309.4 — Operable parts force ≤ 5 lbf

Applies to:Public accommodations and commercial facilities, accessible dwelling units, and projects voluntarily targeting accessibility.

ANSI/BHMA A156.1 — Butt and Surface Hinges(ANSI/BHMA A156.1)

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Builders Hardware Manufacturers Association standard for residential and commercial hinges. Defines bearing types (plain / ball-bearing), grade levels, dimensional tolerances, and application rules used by Hager, Stanley, Bommer, and McKinney.

Key Requirements:

•Grade 1 — heavy-duty commercial; ball-bearing required
•Grade 2 — standard commercial / premium residential
•Grade 3 — standard residential (passage and privacy doors)
•Hinge count by door height — ≤ 60 in. = 2 hinges, ≤ 90 in. = 3, ≤ 120 in. = 4, plus 1 for every additional 30 in.
•Heavy-door bump — add 1 hinge for doors > 200 lb or > 48 in. wide regardless of height

Applies to:All residential and commercial butt and surface hinges sold in the United States.

ANSI/BHMA A156.2 — Bored and Preassembled Locks and Latches(ANSI/BHMA A156.2)

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Performance and durability standard for bored locksets — the residential standard knob and lever sets (Schlage, Kwikset, Yale, Defiant). Defines functions (passage F75, privacy F76, keyed F81/F82/F109), grade levels, and door prep dimensions.

Key Requirements:

•F75 Passage — no lock; latch only (closets, pantries, hallways)
•F76 Privacy — push-button or thumbturn inside, emergency release outside (bedrooms, bathrooms)
•F81 / F82 / F109 Keyed entry — key from outside, thumbturn inside (garage, exterior basements)
•Grade 1 — 800,000 to 1,000,000 cycles
•Grade 2 — 400,000 cycles
•Grade 3 — 200,000 cycles (residential standard)

Applies to:All residential and light-commercial bored locksets sold in the United States.

ANSI/BHMA A115 / A156.115 — Door Preparation(ANSI/BHMA A115 series)

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Door prep dimension standard — 2-1/8 in. cross bore, 1 in. edge bore, 2-3/8 in. or 2-3/4 in. backset, latch face plate 1 × 2-1/4 in., strike mortise 1-1/8 × 2-3/4 in. residential or 1-1/4 × 4-7/8 in. T-strike. Used by every U.S. lockset manufacturer.

Key Requirements:

•Cross bore (face bore) — 2-1/8 in. diameter
•Edge bore (latch bore) — 1 in. diameter
•Backset — 2-3/8 in. residential or 2-3/4 in. commercial / heavy
•Latch face plate mortise — 1 × 2-1/4 × ~1/8 in. deep
•Strike mortise — 1-1/8 × 2-3/4 in. residential or 1-1/4 × 4-7/8 in. extended T-strike

Applies to:All bored-lockset residential and light-commercial door preparations in North America.

ANSI/BHMA A156.18 — Materials and Finishes(ANSI/BHMA A156.18)

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Standardizes the 3-digit BHMA finish codes used on every U.S. door hardware spec sheet. Cross-references the legacy 'US' codes (US3, US26D, US32D, etc.) common in the field.

Key Requirements:

•619 (US15) Satin nickel — most common residential interior finish
•626 (US26D) Satin chromium — common on commercial
•613 (US10B) Oil-rubbed bronze — traditional / craftsman residential
•622 (US19) Matte black — modern / contemporary residential
•630 (US32D) Satin stainless — coastal / high-humidity

Applies to:All residential and commercial hardware spec sheets and millwork submittals.

NFPA 80 — Fire Doors and Other Opening Protectives(NFPA 80)

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Inspection, testing, and maintenance standard for fire-rated assemblies. The only routine residential boundary is the garage-to-dwelling 20-minute fire-rated assembly per IRC R302.5.1. The assembly must bear a UL or Warnock Hersey label, have a self-closer, and use intumescent gasketing if the listing specifies it.

Key Requirements:

•Listed and labeled assembly — door, frame, hardware all part of the listing
•Self-closing device required
•Intumescent or smoke gasketing per listing
•No field modifications that void the label
•Annual inspection in commercial; not enforced in single-family residential

Applies to:Garage-to-dwelling 20-minute assemblies and any fire-rated opening in mixed-use residential.

WDMA / AWI Industry Standards for Wood Doors(WDMA I.S.1A / AWI 0700)

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Window and Door Manufacturers Association (WDMA) and Architectural Woodwork Institute (AWI) standards for wood door construction, performance, and installation tolerances. Defines hollow-core vs solid-core construction, veneer grades, and dimensional tolerances used by Masonite, JELD-WEN, Reeb, Steves & Sons, TruStile, and Simpson.

Key Requirements:

•I.S.1A Architectural wood flush doors — hollow vs solid core construction
•Veneer grades — Premium (AA), Custom (A), Economy (B)
•Dimensional tolerance — width / height ± 1/16 in., squareness ± 1/8 in. across diagonals
•Stile-and-rail door requirements — solid lumber stiles ≥ 1-1/8 in., panels per spec
•AWI 0700 installation — tolerance for jamb plumb, head level, racking

Applies to:All architectural and residential wood doors sold and installed in the United States.

Standards Disclaimer: Standards and codes are subject to periodic updates. Always verify current requirements with local building authorities and professional engineers before beginning construction. Links provided are for reference only.

Egress and Garage Door Code Adoption

IRC R311.2 and R302.5.1 are model code — local amendments matter

Most U.S. jurisdictions adopt the IRC, often two cycles behind the current edition. The egress and garage-door rules above are the most common but not universal — California, Florida, Washington, and several large cities run amended codes that change the specifics.

Regional Examples:

California (CRC):Adopts IRC with amendments. Title 24 energy provisions affect glazing requirements; CALGreen affects formaldehyde / VOC limits on composite-wood doors. Garage door must also have a 20-min listed assembly when the wall is rated.

Florida (FBC-R):Hurricane impact zones — interior doors are not impact-rated, but doors to attached garages in HVHZ areas may need additional fastening detail per FBC-R 308.6.

Washington / Oregon (WSEC / OSSC):Energy code more stringent than IECC base; affects garage door insulation but not interior doors directly. Adopts IRC otherwise.

Northeast (most states):Adopts IRC with minor amendments. R311.2 / R302.5.1 / R308.4 enforced as written. Older housing stock may have grandfathered 28 in.–30 in. egress doors that do not net the 32 in. clear — flag during remodel.

Texas / Southeast:Most jurisdictions adopt IRC current or one cycle back. Houston and Austin enforce R302.5.1 strictly and require third-party inspection of the garage-to-dwelling assembly.

Impact: Always verify with the local AHJ before ordering — a non-compliant garage-to-dwelling door fails inspection and delays close-out. The calculator emits the model-code rule but cannot enforce local amendments.

Climate-Driven Construction Selection

Humidity, salt air, and pest pressure change which doors survive 10 years

Hollow-core MDF and engineered solid-core perform well in conditioned interiors but degrade fast in humid or coastal exposure. Solid wood expands and contracts with seasonal RH; steel doors handle weather but rust at the edges in salt air. Pocket-frame humidity warpage is a regional issue in the Gulf and Southeast.

Regional Examples:

Gulf Coast / Southeast (humid subtropical):Solid-core particleboard slabs over hollow-core wherever possible; pocket frames need acclimation 48 hr in conditioned space; avoid raw MDF cores in any bath. Steel-clad doors get galvanized hinge pins.

Coastal (Florida, NC OBX, CA Pacific, NE Atlantic):Stainless or premium-coated hardware (BHMA 630 satin stainless or 622 matte black powder-coat) — plated brass and bronze finishes pit within 2–5 years inside salt-air conditioned space. Solid wood doors warp; engineered solid core is preferred.

Arid Southwest (NM, AZ, eastern CA, NV):Solid wood stile-and-rail doors dry-shrink 1/16 in.–1/8 in. across the width seasonally — order with 1/8 in. extra width, plane to fit on installation. Hollow-core works fine.

Mountain West / Northern (UT, CO, ID, WY, MT, ND, MN, ME):Wide seasonal RH swings cause stile-and-rail panel cracks if not acclimated. Engineered solid-core is the safer specification.

Pacific Northwest:Stable mild-humid; almost any construction works. Solid wood is the regional preference in custom craftsman / arts-and-crafts work.

Impact: Wrong construction in a humid coastal home means the door warps, the latch fails, and the homeowner replaces it within 3 years. The DOM hinges and lockset cost more to replace than the upgraded slab would have at install.

Wall Framing and Jamb Depth

Stock 4-9/16 in. and 6-9/16 in. depths cover most U.S. residential walls

Pre-hung jamb depths are sized to match the framed wall. The two stock depths handle ~95% of U.S. residential interior partitions. Older homes, basements, and exterior plumbing walls deviate often enough that the calculator carries jamb depth as an explicit input.

Regional Examples:

New construction (post-2000):2×4 partition with 1/2 in. drywall both sides → 4-9/16 in. stock jamb. 2×6 plumbing wall or exterior → 6-9/16 in. stock jamb.

Pre-1960 plaster-and-lath homes:Wall thickness varies 4-3/4 in.–5-1/4 in. depending on lath type and plaster build. Pre-hungs require field-applied jamb extensions on the order of 1/4 in.–1/2 in.

Pre-1940 in cities (NYC, Boston, Chicago, Philadelphia):True 2-inch lumber and thicker plaster — wall sections often 5-1/2 in.–6 in. Jamb depth must be measured on every opening; do not assume stock fits.

Basements with masonry or block walls:Furring strips on the masonry plus drywall yields 7 in. or thicker walls. Custom jamb depth ordered per opening; stock pre-hungs do not fit.

Multi-family / condo with sound walls (STC 50+):Double-stud or staggered-stud walls with resilient channel — wall depths 7 in.–10 in. Custom jamb depth and gasketed perimeter required.

Impact: Wrong jamb depth means field-applied extensions on every opening — adds ~$30–$60 of labor per opening and a visible joint that has to be caulked and painted. Verify wall thickness before ordering pre-hungs.

Pocket Door Specification by Brand

Three frame brands — three rough opening tables

Johnson, Eclisse, and Cavity Sliders each publish slightly different rough opening dimensions for the same nominal door size. Specify the frame brand on the framing plan and verify before cutting headers. The calculator emits the conservative Johnson 1500 value and an explicit brand-verification note.

Regional Examples:

L.E. Johnson 1500 / 1500HD / 1500SC:Most-spec'd in U.S. residential. RO width = 2 × door + 1 in.; height = door + 4-1/2 in. Standard 2×4 frame; 2×6 (model 1560) accepts up to 3 in. thick door.

Eclisse Classic Single:Italian-imported premium frame. RO width = 2 × door + 2 in.; height = door + 3-3/8 in. Proprietary frame design; do not substitute.

Cavity Sliders TSC:Commercial-grade residential. RO width = 2 × door + 1-1/4 in.; height varies by model. Heavier capacity (220 lb+) suits oversized solid wood and glass doors.

FrameTech / Premium Pocket Door:Various stock and custom widths up to 250 lb capacity. RO published per model — do not use a generic dimension.

Converging double pocket:Two doors meet in the middle, each retracting into its own side cavity. RO width = 4 × door + 1-1/2 in. (Johnson 1555). Wall framing and electrical / plumbing routing must avoid both pocket cavities.

Impact: A pocket frame ordered after the wall is framed to the wrong RO becomes a multi-day rework — header, trimmers, and drywall come back out. Verify the brand and the spec sheet before the carpenter cuts the header.

Resale Expectations and Door Width

32 in. preferred over 30 in. is a current-cycle expectation

30 in. has been the U.S. residential bedroom-door standard for 50+ years, but the home-stager / accessibility consensus has shifted toward 32 in. (and 36 in. on the egress door) for resale-grade work. NAHB / NKBA aging-in-place guidelines push 32 in. minimum on every door, and a growing share of buyers notice the difference.

Regional Examples:

New construction (production builders, all regions):Production builders default to 30 in. bedroom and 28 in. bath to keep cost down. Custom builders default to 32 in. bedroom and 30 in. bath.

Custom and luxury (national):32 in. on every secondary door, 36 in. on primary suite and the egress door. Often 84 in. tall (7'-0") instead of the standard 80 in.

Aging-in-place / universal-design renovations:All doors 32 in. minimum, lever handles, no thresholds — meets ADA-style residential without enforcement. NAHB CAPS-trained renovators flag any sub-32 in. door for replacement.

Multi-family / condo over 4 units:FHA / ANSI A117.1 compliance — Type B units require 32 in. clear on at least one bath and bedroom. Type A (fully accessible) requires 32 in. on every door plus turning radius and grab-bar blocking.

Historic / pre-1940 single-family:26 in.–28 in. bedroom doors are common and grandfathered. Replacing with 30 in. requires header reframing — verify the cost-benefit before scoping.

Impact: On a primary-suite remodel, upgrading from 30 in. to 32 in. on the bedroom door usually means widening the rough opening — 30–60 minutes of carpentry. On resale, the wider door reads as upgraded; the narrower as builder-grade.

Hardware Finish Selection by Decade

Finish trends shift visibly every 10–15 years

Finish is non-numeric — it doesn't change counts — but it drives cost noticeably (matte black premium vs satin nickel commodity) and dates a remodel within 10 years. Historic homes have stronger conventions; modern interiors run wider.

Regional Examples:

1990s–2010 builder default:619 satin nickel (US15) — the dominant national finish. Still the safest no-debate choice for new construction.

2015–2025 trend:622 matte black (US19) and 613 oil-rubbed bronze in farmhouse / craftsman; 619 satin nickel still dominant in conservative markets.

Pre-1940 historic restorations:613 oil-rubbed bronze, 643e aged bronze (living finish), or 605 polished brass. Mixing modern matte black on a Queen Anne reads wrong.

Coastal / high-humidity:630 satin stainless or 622 matte black powder-coat over stainless. Plated brass and bronze pit within 2–5 years inside conditioned salt-air homes.

Modern / minimalist:622 matte black, 626 satin chromium, or 622 with concealed bearing hinges. Lever shape (vs round knob) matters more than finish in modern interiors.

Impact: Finish swap on 14 doors in a typical 3-bedroom home: roughly a 1–2 weekend job at $30–$80 per door for hardware. Visible upgrade for the cost — but a finish that dates the room locks the house into a remodel cycle.

Before You Build

•Contact your local building department for specific requirements
•Verify frost line depths, wind zones, and seismic requirements for your area
•Check if permits are required and schedule required inspections
•Consult with a local contractor familiar with local codes

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Per-door rough openings, hinges, locksets, casing LF, and IRC flags for pre-hung, slab, bifold, bypass, barn, pocket, French, and Dutch doors.

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How to Use This Calculator

Pick whole-house defaults: jamb depth (4-9/16 in. for 2×4 walls / 6-9/16 in. for 2×6), casing profile (2-1/4 in. colonial WM 356 default), and finish grade (paint or stain — drives casing waste factor 10% vs 15%).
Click "Load 3 BR / 2 BA preset" for a typical 14-door inventory, or "Add door" to build your own list one room at a time.
For each door, set: room / location, type (pre-hung passage / slab / bifold / bypass / barn / pocket / French double / Dutch), construction (hollow core / solid core / solid wood / MDF / glass / steel-fire), width, height, and thickness.
For bifold, bypass, and barn — also enter the opening width (track and panel sizing depend on it; pre-hungs and pockets size from the slab itself).
Pick lockset function (passage F75 / privacy F76 / keyed F81-F82 / dummy / pocket privacy or pocket passage with edge pull) and hardware finish (619 satin nickel default).
Toggle code flags per door: adjoins garage (R302.5.1), opens into a sleeping room (prohibited from the garage), has glass (R308.4 safety glazing), and self-closer required.
Click Calculate — see per-door rough openings, hinge count and size, casing LF, plus an aggregated hardware bill (kits, hinges by size, locksets by function, pulls, bolts, astragals, stops) and explicit code-flag warnings for IRC R311.2 / R302.5.1 / R308.4 violations.

How the egress and garage-door checks work

IRC R311.2 requires at least one egress door per dwelling that provides ≥ 32 in. clear × ≥ 78 in. clear opening, side-hinged. The clear width is measured between the face of the door and the stop with the door open 90° — door thickness, hinge offset, and stop reduce a nominal width by approximately 2–2-1/2 in., so a 36 in. nominal door is required to net the 32 in. clear. The calculator flags any house where no specified swing door is 36 in. × 80 in. or larger. IRC R302.5.1 requires the garage-to-dwelling door to be solid wood or solid / honeycomb-core steel ≥ 1-3/8 in., or a 20-minute fire-rated assembly with self-closer. A door from the garage may NOT open into a sleeping room — the calculator emits an explicit error if you toggle "adjoins garage" + "opens into a sleeping room" on the same door. IRC R308.4 requires safety glazing (tempered or laminated) on all glass within doors and within a 24-inch arc of door edges below 60 in. AFF — toggle the "has glass" checkbox and confirm safety glazing per spec sheet.

Frequently Asked Questions

What rough opening do I need for a pre-hung interior door?

For a single pre-hung swing door: rough opening width = door width + 2 inches; rough opening height = door height + 2-1/2 inches. The 2-inch width allowance covers ~3/4 inch of jamb stock on each side plus ~1/4 inch of total shim and adjustment space; the 2-1/2 inch height covers the head jamb plus a floor-to-jamb gap for finished flooring. Examples: a 30 × 80 inch pre-hung needs RO 32 × 82-1/2 in.; a 36 × 80 inch needs 38 × 82-1/2 in. This is the universal rule across EZ-Hang, Builders Surplus, MMI Door, Masonite, and JELD-WEN install guides. The rough opening diagram shows the door-plus-2-inch rule.

What rough opening does a pocket door need?

The conservative Johnson 1500-series formula is: RO width = (2 × door width) + 1 inch; RO height = door height + 4-1/2 inches. So a 30 × 80 inch pocket door needs 61 × 84-1/2 in.; a 36 × 80 needs 73 × 84-1/2; a 36 × 96 needs 73 × 100-1/2. Pocket frames vary by brand: Eclisse Classic uses 2W + 2 in.; Cavity Sliders TSC uses 2W + 1-1/4 in. Verify against the specified frame brand before framing — the cavity is full wall thickness, so plumbing, electrical, and structural elements cannot be located in the pocket.

How wide should a barn door be for the opening?

Barn door width = opening width + 4 to 6 inches (2–3 inches of overlap on each side; 3 inches per side is the privacy default for bedrooms and bathrooms). Door height = opening height + 1 inch. Track length must be at least 2× the slab width so the door fully clears the opening — round up to the next stock length (72, 78, 84, 96, 120, or 144 in.). The track must lag into studs or a continuous 1×4 / 1×6 backer board screwed to studs along the entire length. Per Real Sliding Hardware, Rustica, and Goldberg Brothers technical sheets.

How many hinges does an interior door need?

Per ANSI/BHMA A156.1: 2 hinges for doors up to 60 inches tall (rare in residential), 3 hinges for 60–90 inch doors (standard 80 and 84 inch residential), 4 hinges for 90–120 inch doors (96 inch tall), and one extra hinge per additional 30 inches. Add one more hinge for any door heavier than 200 lb or wider than 48 inches regardless of height. A standard 30 × 80 inch interior door uses three 3-1/2 × 3-1/2 inch hinges. A 1-3/4 inch solid-core or fire-rated door bumps to 4 × 4 inch ball-bearing hinges; a 96 inch tall door takes 4 hinges; a 36 × 96 inch oversized door takes 4 hinges and may bump to 4-1/2 inch. The hinge schedule diagram shows the 5/10 placement rule.

What does IRC R311.2 require for the egress door?

At least one egress door per dwelling must provide a 32-inch minimum clear width × 78-inch minimum clear height, side-hinged, openable from inside without a key or special knowledge. Clear width is measured between the face of the door and the stop with the door open 90° — door thickness, hinge offset, and stop reduce the dimension by approximately 2 to 2-1/2 inches, so a 36-inch nominal door is required to net the 32-inch clear opening. Other interior doors are not bound by R311.2 minimums (the code explicitly states 'other doors shall not be required to comply with these minimum dimensions'). The calculator flags any house where no specified door achieves the 36 × 80 minimum.

What does the door from the garage to the house need to be?

Per IRC R302.5.1: solid wood at least 1-3/8 inches thick, OR solid / honeycomb-core steel at least 1-3/8 inches, OR a 20-minute fire-rated assembly bearing a UL or Warnock Hersey label. The door must have a self-closing and self-latching device. Hollow-core is prohibited. The door from the garage may NOT open into a sleeping room — re-route through a habitable space (mudroom, hall, or stair landing). The standard residential spec is a 32 × 80 × 1-3/4 inch steel-clad 20-minute fire-rated pre-hung with three 4-inch ball-bearing hinges, keyed entry lockset, and self-closer.

Can I use a hollow-core door for a bedroom or bathroom?

It will pass code, but acoustic performance is poor. Hollow-core doors deliver STC 17–22 — about as much sound isolation as no door at all. Solid-core doors (particleboard or MDF core) deliver STC 28–35 and are the residential comfort upgrade. Solid wood stile-and-rail goes 30–35 STC depending on density; mineral-core acoustic doors with full-perimeter gasketing and a drop seal can hit 32–36 STC but are uncommon in residential interiors. The calculator defaults to solid core for bedrooms and bathrooms and hollow core for closets, pantries, and secondary spaces.

How is bifold sized — and how many panels do I need?

Bifold doors are sold per the nominal opening size, with the slab undersized 1/2 inch so the as-supplied panels fit the rough opening. Openings up to 36 inches use a single pair (2 panels). Openings 37–72 inches use a double pair (4 panels). Openings over 72 inches use a triple pair or custom configuration. RO width equals the nominal opening — no allowance added — and RO height is door height + 2 inches (a head jamb is mounted but no jamb sits on the slab). Examples: 36-inch closet → 2 panels at 18 inches each, 1 knob; 72-inch linen closet → 4 panels at 18 inches each, 2 knobs. The door type sizing diagram compares swing, barn, bypass, and pocket.

What hardware comes with a French / double door pair?

Six hinges (3 per leaf on standard 80-inch doors), 1 active lockset on the operating leaf, 1 dummy trim on the inactive leaf, 1 pair of flush bolts mortised into the inactive leaf at top and bottom, 1 astragal (vertical strip on the inactive leaf's meeting edge that overlaps the active leaf), and 3 strike plates (active lockset + top and bottom flush bolt strikes). Rough opening = (2 × door width) + 2 inches × door height + 2-1/2 inches. The active leaf carries the daily lockset; the inactive is bolted closed and only opened to move furniture. Glass in any door must be safety-glazed (tempered or laminated) per IRC R308.4.

Interior Doors Calculator