Brick Calculation Formula: Bricks, Cement & Sand for Any Wall

Brick calculation formula for a wall: four steps

Every brick estimate an Indian site engineer makes follows the same four steps. The calculator above does them instantly, but it helps to know them, both to check a contractor's figure and to teach a new supervisor.

Step 1  Wall volume       = Length × Height × Thickness  (minus openings)
Step 2  Brick + joint     = (L + j) × (W + j) × (H + j)
Step 3  Number of bricks  = Wall volume ÷ (brick + joint volume)
Step 4  Order quantity    = Bricks × 1.05   (5% wastage)

With a traditional 9 × 4½ × 3 inch brick (230 × 110 × 75 mm) and a 10 mm joint, one brick plus mortar takes 240 × 120 × 85 mm = 0.002448 m³, so a cubic metre of brickwork holds about 408 bricks. A modular IS 1077 brick (190 × 90 × 90 mm, 200 mm cube with joints) gives 500 per m³.

9 inch brick wall calculation

A 9-inch (one-brick) wall is 230 mm thick. Take a wall 20 ft long and 10 ft high:

1. Area = 20 × 10 = 200 sq ft = 18.58 m².
2. Volume = 18.58 × 0.23 = 4.27 m³.
3. Bricks = 4.27 ÷ 0.002448 ≈ 1,746, or about 1,835 with 5% wastage.
4. That works out to roughly 8.7 bricks per square foot of a 9-inch wall, and about 4.4 for a 4½-inch wall.

Brick calculator in square feet

If the wall is measured in square feet, multiply the area by the bricks per square foot for that thickness: about 8.7 for 9 inch and 4.4 for 4½ inch with traditional bricks and 10 mm joints. Use the calculator for other brick sizes or joints.

Cement and sand for brickwork mortar

Mortar fills the space between bricks, roughly a quarter of the wall's volume. Wet mortar shrinks when mixed, so the dry volume is taken as 1.33 times the wet volume. For a 1:6 mix (common for walls in houses), one part is cement and six parts sand:

Brick calculation formula in Excel

For a quick sheet, put length (ft) in A2, height (ft) in B2 and thickness (ft, 0.75 for 9 inch) in C2. This brick calculation formula in Excel uses a traditional brick with a ⅜-inch joint (0.0313 ft):

=ROUNDUP((A2*B2*C2)/((0.75+0.0313)*(0.375+0.0313)*(0.25+0.0313))*1.05,0)

The same steps work as a bricks calculation formula in feet on paper: wall cubic feet ÷ cubic feet of one brick with its joint.

Brick calculation formula in Pakistan

Builders in Lahore, Karachi and Faisalabad mostly use the 9 × 4½ × 3 inch standard brick, the same nominal size as the traditional Indian brick, with a ⅜ inch joint. The brick calculation formula in Pakistan is therefore identical: a 9-inch wall needs about 8–9 bricks per square foot and a cubic foot of brickwork about 11 bricks. Choose “Pakistan standard” in the calculator to apply that exact size.

Common mistakes in brick estimates

• Forgetting openings: deduct doors, windows and ventilators; the calculator has a field for it.
• Using inside dimensions only: measure the centre line of walls, or corners get counted twice.
• Adding wastage twice: add 5% once, at the end.
• Mixing units: keep everything in feet or everything in metres.

Ordering sand by truck? Convert the sand quantity to brass with the brass calculator.