Tap & Trowel Home-project calculators & repair guides

Brick calculator

Enter the wall’s length and height and any openings to get the number of clay bricks from Brick Industry Association Technical Note 10, plus mortar volume and a waste allowance. Defaults: 25 ft × 4 ft wall, modular brick, ⅜ in joints, 5% brick waste (BIA’s “at least 5%” guidance).

By Jordan Hale · Updated

Units
Doors, windows or vents, total area.

Counts and mortar volumes come from BIA TN 10 Table 4 (running or stack bond).

Brick count is the same for both joints; mortar volume changes.

BIA TN 10: add at least 5% for breakage and waste after other corrections.
Optional: estimate the cost

Enter today’s price per brick. Nothing is pre-filled. Mortar bags and delivery are not included.

You need about

bricks
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Wall area (ft²)
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Courses (rows)
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Mortar (ft³)
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Mortar (yd³)
–
Masonry cement bags (rule of thumb)
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Cost
–

Brick count includes your waste % and is rounded up. Mortar uses BIA Table 4 net volume plus a separate 20% waste allowance (midpoint of BIA’s 15–25% mortar waste band). The cement-bag figure is BIA’s rough rule of thumb: 8 bags per 1,000 modular brick (includes unspecified waste)—use it only as a starting point.

Illustration of a low red-brick garden wall being laid in running bond, with a stack of spare bricks, a mortar board and a brick trowel on the gravel beside it.
Illustration

How the calculator works

  1. Wall area: length × height, minus openings.
  2. Bricks: BIA TN 10 Table 4 gives bricks per 100 ft² for common sizes (for example, 675 modular, 655 standard, 450 Norman, 300 utility). Multiply by net area, add waste, and round up.
  3. Mortar: Table 4 lists cubic feet of mortar per 100 ft² for ⅜ in and ½ in joints (net). We add 20% waste by default (within BIA’s 15–25% mortar waste guidance).
  4. Courses: from BIA vertical coursing (for example, modular and standard: three courses = 8 in).
  5. Masonry cement bags: BIA’s rough rule of thumb is eight bags of masonry cement per 1,000 modular brick. It is not a precise yield.

Worked example

A garden wall 25 ft long and 4 ft high, no openings, modular brick, ⅜ in joints, 5% brick waste:

  • Area: 25 × 4 = 100 ft². Bricks: 675 × 1.05 = 708.75 → 709 bricks in 18 courses (three courses = 8 in).
  • Mortar (net): 5.5 ft³; with 20% waste ≈ 6.6 ft³ (about 0.24 yd³).
  • Cement bags (rule of thumb): 709 ÷ 1000 × 8 ≈ 5.7 → 6 bags.

Assumptions and limits

  • Single-wythe running or stack bond as in BIA Table 4. Header patterns (common, Flemish, English) need BIA Table 6 correction factors—not applied here.
  • Solid or fully bedded brick with coring up to about 25% of the bed area. Hollow units with face-shell bedding use less mortar.
  • No collar joint between wythes. Multi-wythe walls need extra mortar from BIA Table 5.
  • The footing isn’t included. Work out its concrete with the concrete calculator.
  • For concrete masonry (CMU), use the cinder block calculator—those quantities come from NCMA TEK 4-2A, not BIA TN 10.
Before you build.

Call 811 at least a few days before you dig a footing so buried utility lines can be marked. Under the International Residential Code, retaining walls over 4 ft (measured from the bottom of the footing), or any wall holding back a driveway, slope or structure, need a permit, and walls retaining more than 4 ft of soil must be engineered; local rules can be stricter. Brick and mortar are heavy: get help, lift with your legs, and wear gloves and eye protection. Cutting brick makes silica dust, so use a wet saw or a saw with a dust collector and wear a respirator.

Related: cinder block calculator, concrete calculator, gravel calculator, cubic yard calculator and how to build a retaining wall.

Sources

How this page was made. Jordan Hale is the author and is responsible for this page. An AI assistant helped write the code, gather manufacturer data and draft the explanation. The math is covered by automated tests against the published reference values cited below. The calculator gives a planning estimate. It does not replace the product label, your supplier or an engineer. The illustration on this page is AI-generated and shows the general idea, not exact construction details.