Remodel Planning: Calculators, Diagrams & Guides
7 calculators · 20 diagrams · 5 guides
A room remodel is a dozen trades sharing one set of dimensions — and estimating it trade by trade means re-entering the same room size a dozen times and missing the places where trades overlap. The seven composers in this hub work differently: enter the room dimensions once and each one orchestrates the relevant single-trade calculators (drywall, paint, flooring, tile, and more) into a single merged materials list, with every line item traceable back to the calculator that produced it.
The composers also resolve what trade-by-trade estimating double-counts: when wall tile covers the lower half of a bathroom wall, the paint takeoff automatically shrinks by the tiled area, so you buy gallons for the wall that will actually be painted. The diagrams in this hub map each room’s composer flow, the surface-overlap deductions, and the code gates that shape each conversion — basement egress under IRC R310, attic headroom under R305.1, and garage conversion requirements.
When the question shifts from materials to budget, each room links to its dedicated cost guide, where ranges are computed from a centralized, dated cost model — wide brackets by design, because honest ranges age better than fake precision. Every composer is free, requires no signup, and states plainly what it does not include.
Remodel Planning calculators
- Bathroom Remodel CalculatorCombine drywall, paint, flooring, and wall-tile estimates into one bathroom materials list. Tile-vs-paint overlaps handled automatically. Free.
- Kitchen Remodel CalculatorCombine drywall, paint, flooring, and backsplash tile estimates into one kitchen materials list. Backsplash-vs-paint overlap handled. Free.
- Basement Remodel CalculatorLive basement finishing cost range — pick scope, size, finish, region. Egress, bath, sewage ejector adders explained. Free, no signup.
- Garage Conversion CalculatorLive garage conversion cost — bonus room, habitable, or full ADU. Egress, mini-split, foundation, service upgrade adders. IRC/IECC callouts. Free.
- Attic Conversion CalculatorLive attic conversion cost — bonus room, habitable, or full ADU. Dormer, stair, joist sister, mini-split adders. IRC R305.1 & R310 callouts.
- Laundry Room Remodel CalculatorLive laundry room remodel cost range — typology, finish, floor level, plumbing & electrical adders. IRC P2706, NEC 210.8 callouts. Free, no signup.
- Home Addition Cost CalculatorFree home addition cost calculator — instant low/likely/high price ranges by addition type, foundation, finish, and region. Soft costs itemized.
Cost guides
Budget-level price ranges per room, computed from a dated cost model — wide brackets by design, updated on an annual review.
- How Much Does a Bathroom Remodel Cost in 2026?
- How Much Does a Kitchen Remodel Cost in 2026?
- How Much Does It Cost to Finish a Basement in 2026?
- How Much Does an Attic Conversion Cost in 2026?
- How Much Does a Garage Conversion Cost in 2026?
- How Much Does a Laundry Room Remodel Cost in 2026?
- How Much Does a Home Addition Cost in 2026?
Guides & references
Remodel Planning · 20 diagrams
- Remodel Planning
Building out vs. building up — why a second-story addition costs more per square foot
Out vs. up is the first cost decision. Building out needs a NEW foundation and roof and eats yard/setback, but leaves the house alone. Building up keeps the footprint and reuses the foundation — but you pay to reinforce the existing structure and rebuild the roof, which is why second-story work runs ~$300–$500/SF vs. ~$200–$350/SF for a ground-floor addition.
- Remodel Planning
Four ways to support an addition — slab, crawlspace, basement, or none (cantilever), cheapest to priciest
Foundation is the biggest single structural cost swing. Slab-on-grade is the cheapest baseline; a crawlspace adds ~3–8%; a full basement adds ~15–35% (the biggest swing); and “none” — a cantilevered bump-out or building over the existing floor — costs slightly less. In cold climates footings must reach below the frost line (IRC R403.1.4).
- Remodel Planning
How a bathroom remodel composer works — one room feeds seven calculators into one materials list
A composer never re-implements math. You enter the bathroom once, and the shared dimensions feed seven standalone calculators (drywall, paint, flooring, wall tile, vanity, countertop, trim). Each runs on its own, then the outputs merge into one materials list where every line traces back to its source calculator.
- Remodel Planning
Bathroom paintable wall area — subtract doors, windows, and tiled surfaces from the wall area
Paintable wall = wall area − doors − windows − tiled surfaces. In an 8 ft × 5 ft bath with an 8 ft ceiling: 208 − 20 (door) − 15 (window) − 66 (tub-surround tile) = 107 sf painted. Subtracting the tiled area so paint isn’t over-bought is the whole reason composers exist.
- Remodel Planning
Bathroom wet-area tile — tub surround (66 sf) vs. walk-in shower (77 sf) unfolded
A wet-area preset is three alcove walls unfolded: a 5′ back wall + two 3′ end walls = 11 LF of tile. Height sets the rest — a tub surround tiled to 6 ft is 11 × 6 = 66 sf; a walk-in shower tiled to 7 ft is 11 × 7 = 77 sf. This tiled area feeds the wall-tile calculator and is deducted from paint.
- Remodel Planning
How a laundry room remodel composer works — five calculators plus three code-derived trades merged into one list
The laundry composer is hybrid. Pick the scope once and it delegates to five standalone calculators (drywall, paint, flooring, trim, interior doors), then derives the three trades with no calculator yet — plumbing, electrical, dryer vent — from code-anchored rules of thumb. Every merged line is tagged with its source.
- Remodel Planning
Washer standpipe rough-in — 18 to 42 inches above the trap weir with a 2-inch vented P-trap
Set the top of the washer standpipe 18–42″ above the trap weir (IRC P2706.1.2), with a 2″ vented P-trap (Table P3201.7). The discharge hose sits loose in the open top as an air gap. An S-trap is banned here — it self-siphons its seal on the washer’s fast discharge and lets sewer gas in.
- Remodel Planning
Dryer-vent developed length — 35-foot maximum minus 5 feet per 90-degree elbow and 2.5 feet per 45
A 4″ dryer duct is capped at 35 ft of developed length (IRC M1502.4.6.1) — but each 90° elbow costs 5 ft and each 45° costs 2.5 ft. Two 90s and a 45 leave 35 − 10 − 2.5 = 22.5 ft of straight duct. Foil-tape the joints (no screws — they snag lint); the wall cap gets a damper and no screen.
- Remodel Planning
How a garage conversion calculator works — one garage feeds many trade calculators into one list
A composer never re-implements math. You describe the garage once, and the shared inputs feed the standalone trade calculators — framing, insulation, drywall, subfloor, flooring, paint & trim, egress windows, HVAC. Each runs on its own, then the outputs merge into one list where every line traces back to its source calculator.
- Remodel Planning
Garage slab slopes to drain — level it with SLU, sleepers, or dimpled panels before flooring
A garage slab is pitched ~⅛″ per foot toward the door to drain (IRC R309.1), so you can’t floor over it flat — the low end leaves a wedge gap. Level the plane first: self-leveling underlayment for small slope + tile/LVP, PT sleepers + plywood for hardwood or cold climates (cavity takes R-10 foam), or dimpled floating panels for floating floors in mild climates.
- Remodel Planning
Garage to living space — three code jumps: insulate (IECC), egress window (IRC R310), add HVAC
A garage becomes living space by clearing three code jumps, each adding materials: (1) insulate walls + ceiling to the IECC minimum for the zone; (2) add an egress window per bedroom — IRC R310 wants ≥5.7 sf clear, ≥24″ high, ≥20″ wide, sill ≤44″ up; (3) add the new load to HVAC (Manual J) or a mini-split, since the garage was never conditioned. This is why a conversion is more than drywall and flooring.
- Remodel Planning
How a kitchen remodel composer works — one kitchen feeds seven calculators into one materials list
A composer never re-implements math. You enter the kitchen once, and the shared dimensions feed seven standalone calculators (drywall, paint, flooring, backsplash tile, cabinets, countertop, trim). Each runs on its own, then the outputs merge into one materials list where every line traces back to its source calculator.
- Remodel Planning
Kitchen backsplash zone — the 18″ band between the 36″ counter and 54″ upper cabinets
A kitchen backsplash is a band, not a whole wall: standard tile fills only the 18″ between the 36″ counter and the 54″ upper cabinets, so tiled area = run (LF) × 1.5 sf/ft. A full-height run tiles counter-to-ceiling (LF × 5.0 on an 8 ft ceiling) and a 4 ft range feature adds ~20 sf. This tiled area feeds the backsplash-tile calculator and is subtracted from the paintable wall.
- Remodel Planning
Kitchen cabinet count from linear feet — runs divided by average box width, rounded up
Linear feet become a whole-cabinet count: cabinets = run (LF) × 12 ÷ average width, rounded up. Base and wall cabinets average 24″, tall pantry 30″ — so 16 LF base = 8 cabinets, 12 LF wall = 6, 2.5 LF tall = 1. The countertop rides the base run, so the same 16 LF also sizes the slab (× ~25.5″ deep ≈ 34 sf before waste).
- Remodel Planning
How a basement remodel calculator works — one basement feeds ten trade calculators into one list
A composer never re-implements math. You describe the basement once, and the shared inputs feed ten standalone trade calculators — framing, insulation, a rim-joist air-seal, drywall, paint, flooring, doors, egress windows, trim, HVAC. Each runs on its own, then the outputs merge into one list where every line traces back to its source calculator.
- Remodel Planning
Finished basement perimeter wall — foundation, rigid foam, stud wall, batt, drywall, and rim-joist air-seal
A finished basement wall is a layered assembly built inboard of the concrete foundation: continuous rigid foam (R-5), a 2×4 stud wall off the concrete, unfaced cavity batt (R-15), and ½″ drywall + paint. Two basement-only details — a pressure-treated bottom plate where wood meets the slab (IRC R317.1) and a closed-cell rim-joist air-seal — are what make it dry and tight. The composer counts studs, batts, sheets, and gallons from this one wall.
- Remodel Planning
Basement bedroom egress window — IRC R310 clear-opening, sill height, and window-well minimums
Any basement bedroom needs a code-legal egress window (IRC R310): a net clear opening ≥ 5.0 sq ft (the below-grade exception; 5.7 sq ft above grade), ≥ 20″ wide and ≥ 24″ tall at the same time, with the sill ≤ 44″ above the finished floor. Below grade it sits in a window well ≥ 9 sq ft that needs a permanent ladder once it is deeper than 44″, and it must open from inside without keys or tools.
- Remodel Planning
How the attic-conversion composer builds one materials list from a dozen calculators
The attic-conversion calculator is a composer: you enter the attic once and it feeds a dozen standalone calculators, then merges their outputs into one list where every line traces back to its source. An attic pulls in more trades than most rooms — knee-wall framing, a reinforced subfloor, insulation at the roofline, and stairs all stack onto the same footprint.
- Remodel Planning
Attic headroom rule — code only counts floor area under a 7-foot ceiling (IRC R305.1)
Code only counts attic floor area that sits under a 7-ft ceiling. Area below 5 ft doesn’t count at all, the sloped 5–7 ft band is usable but doesn’t satisfy the minimum, and at least half the required floor area must be a full 7 ft or taller — so a big raw attic often becomes a much smaller legal room. Knee walls close off the low triangle; a dormer is how you grow the tall zone.
- Remodel Planning
Attic floor gate — ceiling joists carry 10 psf, a room needs 30–40 psf (IRC Table R301.5)
The floor is the gate most attic conversions fail. Ceiling joists (often 2×6) were sized for a 10 psf attic — enough to hold drywall and boxes, not people. A habitable room needs 30 psf (sleeping) to 40 psf (other rooms), so the joists almost always must be sistered with a deeper member or doubled up, and deepened to keep deflection within L/360, before any finishes go on.
Frequently Asked Questions
How is a room composer different from a single calculator?
A composer never does its own math — it feeds your room dimensions to the same single-trade calculators you could run individually (drywall, paint, flooring, tile), then merges their outputs into one materials list with a source label on every line. You get a whole-room takeoff with the traceability of the individual tools, and one place to change a dimension.
Do the remodel calculators include labor or fixture costs?
No — composers output materials only: quantities, units, and the calculator each line came from. Plumbing fixtures, electrical, cabinetry boxes, and labor are excluded and said so on each page. For budget-level numbers, each room links to its cost guide, which shows ranges from a dated cost model rather than quoting precise totals that would go stale.
What code requirements come up when finishing a basement or attic?
The two big gates: sleeping rooms need IRC R310 emergency egress (a window or door with 5.7 sq ft of clear opening, max 44-inch sill), and habitable attic space needs R305.1 ceiling height — 7 feet over at least half the required floor area. The basement and attic composers surface both checks, and the hub diagrams illustrate the geometry.
Why does the bathroom calculator reduce my paint quantity when I add wall tile?
Because the tiled area is not painted, and buying paint for it wastes gallons. The composer computes the tile wainscot area from your wet-area preset and subtracts it from the paintable wall area before the paint calculator runs — the surface-overlap resolution that is the whole reason composers exist. The deduction shows in the paint line’s notes.
Can I use the home addition calculator for a full new build?
No — it is scoped to residential additions: new conditioned space attached to an existing structure, from foundation through finishes. A ground-up house involves site work, utilities, and structural engineering outside its model. For an addition it produces the merged multi-trade materials list and links to the addition cost guide for budget ranges.