20 × 10 ft wall, 9 inch thick, one 21 sq ft door, 5% wastage
16.6 m² of wall. About 1,747 bricks, 5 bags of cement and 0.83 m³ of sand for the mortar.
Brick calculator
A standard modular brick of 190 × 90 × 90 mm laid with 10 mm mortar, which makes 200 × 100 × 100 mm. Mortar is 1:6 cement to sand with 27% extra for dry volume. Openings are taken off the wall area.
ft
ft
Wall thickness
sq ft
%
Bricks needed
1,747
16.6 m² of wall, 100 bricks per m² plus 5% wastage. Mortar needs about 5 bags of cement and 0.83 m³ of sand.
- Wall area
- 16.6 m²
- Cement
- 5 bags
- Sand
- 0.83 m³
Counting bricks for a wall
A mason will count bricks by rule of thumb, but the sum behind it is just volume. A modular brick with its mortar joint takes up 200 × 100 × 100 mm, so a cubic metre of wall holds about 500 of them.
That makes a 9 inch wall, one brick thick at 200 mm, about 100 bricks per square metre. A 4.5 inch half-brick wall is 50 per square metre. Take a 20 × 10 ft wall with a 21 sq ft door. The net area is 179 sq ft, which is 16.6 m². At 100 per m² that is about 1,663 bricks, and with 5% wastage you order about 1,747.
Mortar fills the rest of the volume. For that wall it needs about 5 bags of cement and 0.83 m³ of sand at a 1 : 6 mix. Plaster is extra and uses more.
Order a little over, because bricks break on delivery and in cutting. If your local bricks are not the modular size, use the count your supplier quotes per cubic metre instead.
Sources
What this calculator does not account for
- Plaster.
- Brick sizes that differ from the modular size.
- Beams, lintels and pillars.
How this is calculated
Formula: Bricks from wall area
bricks =wall area (m²) × bricks per m² × (1 + wastage)What the symbols mean
- bricks per m²About 100 for a 9 inch wall and 50 for a 4.5 inch wall.
- mortarWall volume minus the volume of the bricks themselves.
Good to know
- A modular brick is 190 × 90 × 90 mm, or 200 × 100 × 100 mm with the mortar joint.
- Mortar is 1 : 6 cement to sand with 27% added for the dry volume.
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Worked examples
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<iframe src="/embed/brick-calculator" title="Brick calculator" width="100%" height="720" style="border:0;max-width:42rem" loading="lazy"></iframe>Questions
How many bricks in a square foot?
About 9 to 10 for a 9 inch wall and about 5 for a 4.5 inch wall, using standard modular bricks.
Do older brick sizes change the count?
Yes. Traditional bricks, about 230 × 110 × 70 mm, give a different count, so check the size from your supplier.
What is the usual wastage?
Around 5%, and more for poor quality bricks.
Is the mortar included?
Yes, the tool estimates cement and sand for a 1 : 6 mortar.