Brick Calculator
How many bricks do you actually need? This free brick calculator covers every common residential application in one tool — anchored brick veneer and multi-wythe solid walls, thin brick accent walls and fireplace surrounds, brick pavers for patios and driveways, and refractory firebrick for fireboxes — with bricks, mortar bags, wall ties, weep holes, base aggregate, polymeric sand, and Heat-Stop pails all derived from the BIA Technical Notes the trade uses.
Brick math is unforgiving. Modular brick at the standard 3/8-inch joint is 6.75 per square foot (BIA TN 10 Table 4); change the joint to 1/4 inch and coverage rises to 7.34, change to 1/2 inch and it falls to 6.40. Mortar volume scales linearly with joint width and adds another 25% waste in the field. Common, English, and Flemish bond add header courses that increase brick count per face by 17–50%. Multi-wythe walls double or triple the count and require collar-joint mortar from BIA TN 10 Table 5. Get any of these wrong and you finish a 3,000-brick wall short by 200 bricks on a Saturday afternoon.
Built on BIA Technical Notes 10 (estimating), 14 (paving), 28 (anchored veneer), 30 (bonds and patterns); ASTM C216 (facing brick), C270 (mortar), C902 / C1272 (pavers), C1088 (thin brick), C199 (refractory mortar); 2021/2024 IRC R703.8 and Chapter 10 (chimneys and fireplaces); TMS 402-22; and ICPI Tech Specs 2 / 3 / 17. Free, no signup.
Brick Calculator
Estimate brick veneer, multi-wythe walls, thin brick accent walls, brick pavers, and firebox firebrick — bricks, mortar bags, ties, weep holes, base aggregate, polymeric sand, and refractory mortar pails.
Application
Wall dimensions
For a gable end, enter the eave height as "wall height" and the additional triangle height as "gable height". The triangle area is added automatically.
Openings
Standard sizes: door 3'×7' ≈ 21 sq ft; window 3'×4' ≈ 12 sq ft; single garage 9'×7' ≈ 63 sq ft; double garage 16'×7' ≈ 112 sq ft.
Brick & joint
Construction details
Wythes = 1 for anchored brick veneer (most residential). Wythes ≥ 2 for solid multi-wythe walls. High seismic / high wind tightens tie spacing from 2.67 sq ft to 2.0 sq ft per tie.
Waste factors
Bond defaults: running 5%, ⅓ running / stack 6%, common 9%, English / Flemish 12%. BIA recommends +15–25% on net mortar; field convention runs +33–50%.
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How to Use This Calculator
- Pick the application: wall brick (anchored veneer or multi-wythe), thin brick veneer, brick pavers, or firebox firebrick. Inputs and outputs change with each mode.
- For wall brick — enter wall length, eave height, and gable height (if applicable). Add doors, windows, and garage doors with their square-footage area each (defaults: 21 / 12 / 63 sq ft).
- Pick the brick size (modular is the US default at 6.75 / sq ft), mortar joint width (3/8" default per BIA TN 10), and bond pattern (running, common, English, Flemish, etc. — each carries its own waste factor).
- Set wythes (1 = anchored veneer, 2+ = solid multi-wythe), mortar type (N for above-grade default, S for below-grade and structural), and seismic / wind exposure (drives tie spacing 2.67 vs 2.0 sq ft per IRC R703.8.4.1).
- For thin brick — enter wall length, height, outside-corner LF, and openings. Pick the thin brick format (modular, Norman, queen, or Brickwebb panel) and application (interior cement-board substrate vs exterior WRB + lath).
- For pavers — enter length × width, pick application (pedestrian / residential drive / heavy / commercial), paver size, and pattern. ICPI Tech Spec 2 base depths default to 4-inch pedestrian, 6-inch driveway, 8+ inch commercial.
- For firebox — enter interior width, height, and depth in inches. Standard firebrick defaults (9 × 4½ × 2½). The calculator computes floor + back + 2 sides separately, sums to total firebrick, and converts to Heat-Stop pails at 100 firebrick per 50-lb pail.
- Click Calculate — see bricks with waste, mortar bag counts (Quikrete #1102 / Sakrete equivalent), wall ties (anchored veneer only), weep holes per IRC R703.8.6, paver base aggregate in cubic yards and tons, polymeric sand in 50-lb bags, edge restraint LF, geotextile sq ft, or refractory mortar pails plus IRC R1001.10 hearth extension dimensions.
How bricks-per-square-foot scales with joint width
Coverage is set by the brick's specified (manufactured) face dimensions plus the mortar joint on each side: bricks per sq ft = 144 / [(specified L + joint) × (specified H + joint)]. For modular brick (specified 7-5/8 × 2-1/4): a 1/4 inch joint yields 7.34/sq ft; the standard 3/8 inch joint yields 6.75; a 1/2 inch joint yields 6.40. The calculator recomputes for any joint width you select and adjusts the BIA TN 10 mortar volume by the same ratio. Common bond (header every 6th course) adds 1/6 to the brick count per face for the header rotation; English bond adds 1/2; Flemish adds 1/3 — all per BIA TN 10 Table 6. Multi-wythe walls multiply by the number of wythes and add collar-joint mortar from BIA TN 10 Table 5. The calculator handles all of this automatically.
Frequently Asked Questions
How many bricks do I need per square foot?
Modular brick (3-5/8 × 2-1/4 × 7-5/8 specified) at the standard 3/8-inch mortar joint covers 6.75 bricks per square foot per BIA Technical Note 10 Table 4 — the universally cited US estimating reference. Other common sizes at 3/8-inch joint: standard 6.55, queen 5.63, Norman 4.50, king 4.55, utility 3.00. The formula is bricks/sq ft = 144 ÷ [(specified L + joint) × (specified H + joint)]. Joint width is the biggest variable: a 1/4-inch joint pushes modular coverage to 7.34 and a 1/2-inch joint drops it to 6.40. Always start by deducting every door, window, and garage opening from the gross wall area, then multiply by bricks/sq ft × bond factor × wythes × (1 + waste).
How many mortar bags do I need per 1,000 bricks?
Two industry numbers exist — the engineering value and the manufacturer rule of thumb — and they bracket the right answer. Engineering: BIA TN 10 Table 4 lists 8.1 cubic feet of mortar per 1,000 modular brick (net, no waste). Add 25% field waste = 10.1 cu ft. Quikrete #1102 yields 0.74 cu ft per 80-lb bag, so 10.1 ÷ 0.74 ≈ 14 bags per 1,000 modular brick. Manufacturer cross-check: Quikrete data sheet states 37 brick per 80-lb bag, which works out to 27 bags per 1,000 — already with substantial waste built in, more conservative for DIY planning. Both values are correct in their own framing — the calculator outputs both so you can pick.
What's the difference between Grade SW, MW, and NW brick?
ASTM C216 / C62 grades face brick by weather-resistance: Grade SW (Severe Weathering) requires minimum 3,000 psi compressive strength, max 17.0% 5-hour boil absorption, max 0.78 saturation coefficient — required wherever the weathering index exceeds 50, which covers most of the contiguous United States. Grade MW (Moderate Weathering) is 2,500 psi and 22% absorption — acceptable above grade in mild climates only (parts of southern Florida and southernmost Texas). Grade NW (Negligible Weathering) is interior-only at 1,500 psi minimum. Per ASTM C216 Appendix X4: "Wherever the weathering index exceeds 50, only Grade SW brick should be used" — this is the most-cited brick selection rule and the reason most US residential veneer is Grade SW.
What mortar type should I use — N, S, or M?
ASTM C270 mortar selection follows the load and exposure: Type N (750 psi) is the default for above-grade brick veneer, parapets, chimneys above the roofline, and interior load-bearing walls. Type S (1,800 psi) is required below grade, for adhered veneer per IBC, and where high flexural-bond strength matters (high-wind / hurricane zones). Type M (2,500 psi) is for below-grade retaining walls, severe lateral / seismic loads, and mortar-set paver setting beds. Type O (350 psi) is for interior non-load-bearing work and historic repointing where existing mortar is soft. Don't use a harder mortar to repoint soft historic brick — the harder mortar transfers stress through the bricks rather than the joints, causing face spalling rather than joint failure.
How many wall ties do I need for brick veneer?
Per IRC R703.8.4.1: standard SDC A/B/C with wind ≤ 30 psf — one tie per 2.67 sq ft of wall area, max spacing 32 inches horizontal × 24 inches vertical. High seismic SDC D₀/D₁/D₂ or wind > 30 psf — one tie per 2.0 sq ft. Add 4 extra ties around every opening larger than 16 inches in either dimension. For a 547 sq ft veneer wall in standard exposure: 547 ÷ 2.67 = 205 base ties × 1.10 contractor allowance = 226 ties, plus 4 × 4 openings = 242 ties total. Use No. 9 wire ties (0.148-inch minimum) hooked into mortar joints, or 22-gauge corrugated × 7/8-inch wide sheet metal ties.
How are weep holes spaced and sized?
IRC R703.8.6 requires weep holes ≥ 3/16-inch diameter, ≤ 33 inches on center, immediately above every flashing course. Locations: base of veneer (full perimeter), above every lintel, under every window sill, at shelf angles, and where veneer meets a roof. Cotton wick weeps, open head joints (no mortar in selected joints), and louvered plastic weeps are all acceptable; never seal weep holes. Through-wall flashing with end dams is required at every flashed course, not just at the base. The 1-inch minimum air space behind the veneer (BIA TN 28 prefers 2 inches) carries water down the back of the wall to the flashing — installing mortar nets or drainage mat keeps dropped mortar from blocking weeps.
How much aggregate base do I need under brick pavers?
Per ICPI Tech Spec 2: pedestrian patios and walkways need 4 inches compacted dense-graded aggregate base over compacted subgrade; residential driveways need 6 inches; streets and commercial drives need 8 to 12 inches per Tech Spec 4. The formula is base (cu yd) = area (sq ft) × depth (ft) ÷ 27. A 200 sq ft pedestrian patio with a 4-inch base needs 200 × 0.333 ÷ 27 = 2.47 cu yd of base. Dense-graded crushed stone weighs ~1.4 tons per cu yd, so that's 3.46 tons. Plus 1 inch (200 ÷ 324 = 0.62 cu yd) of ASTM C33 bedding sand uncompacted, screeded to grade. Geotextile fabric is required between subgrade and base on plastic / silty soils.
How do I figure firebrick for a fireplace firebox?
Standard firebrick (ASTM C27 or C1261) is 9 × 4-1/2 × 2-1/2 inches. Compute the four faces separately: floor pieces lie flat (9 × 4-1/2 = 40.5 sq in footprint per brick), and back / side wall pieces stand as stretchers (9 × 2-1/2 = 22.5 sq in face per brick). For a 36 × 24 × 16 inch firebox: floor = ⌈576 ÷ 40.5⌉ = 15, back wall = ⌈864 ÷ 22.5⌉ = 39, sides = 2 × ⌈384 ÷ 22.5⌉ = 34. Total 88 firebrick + 5% waste = 93. Use medium-duty refractory mortar per ASTM C199 (Heat-Stop premixed at 2,500 °F, Rutland Dry Mix #211 at 2,550 °F) — IRC R1001.8 caps joints at 1/4 inch maximum, and Heat-Stop publishes 100 firebrick per 50-lb pail at 1/16 to 1/8 inch joints (manufacturer recommended).
What's the difference between thin brick and full brick veneer?
Thin brick (ASTM C1088) is 1/2 to 5/8 inch face thickness, capped at 1-3/4 inches max — installed adhered to a substrate (cement board indoors, WRB + metal lath + scratch coat outdoors). Full brick veneer (ASTM C216) is 3-5/8 inches thick, anchored to backing with wire ties, and weighs 39 psf installed (ASCE 7-22). Thin brick weighs only 5 to 7 psf finished — light enough to adhere to standard wood-stud walls without a foundation ledger or shelf angle. Face dimensions match (a Modular thin brick has the same 2-1/4 × 7-5/8 face as a Modular full brick), so the wall reads identical from outside. Thin brick saves real cost on shelf-angle steel, foundation widening, and structural framing — the trade-off is a more demanding installation procedure.
What waste factor should I use for brick?
Per BIA TN 10 / TN 30: running bond and 1/3 running bond — 5 to 7%; stack bond — 5 to 7% (but requires bed-joint reinforcement, not load-bearing); common bond with header every 5th to 7th course — 8 to 12%; English and Flemish bond — 10 to 15% (more cuts at corners, more headers). Soldier, sailor, and rowlock courses add another 2% on top of base. For pavers per ICPI: 5% running bond, 6% basketweave, 8 to 12% 90° herringbone, 12 to 18% 45° herringbone, 15 to 20% circular / radial. Mortar waste defaults to +25% per BIA TN 10 (engineering value); field convention runs +33 to +50% for mortar drops, retempering, and scrap — the calculator uses the BIA value but exposes a manufacturer-rule cross-check (37 brick / bag) that already includes the larger waste assumption.