Brick and Block Calculator
How many bricks or blocks for a wall, with openings taken out and waste added.
Good to know. About 60 bricks make a square metre of wall, which is a lot of bricks for a garden wall.
Approximate. Real-world values vary.
How it works
In plain words
Take the wall area, length times height, minus doors and windows. Divide it by the face of one brick plus its mortar joint, double it for a two-skin wall, and add a little for breakages.
The formula
area = length × height − openings per m² = 1 ÷ ((brick length + joint) × (brick height + joint)) bricks = area × per m² × skins × (1 + waste)
Worked example
A 6 × 1.8 m wall is 10.8 m². A standard brick with a 10 mm joint covers 0.225 × 0.075 m, so 59.3 bricks a square metre: 640, or 672 with 5% extra.
Sources
No outside data or rates: this is plain arithmetic.
6 automated tests check its answers on every change.
About the brick and block calculator
To order bricks or blocks for a wall, work out the area of wall and how many units fit in each square metre or square foot. This calculator does both for the common sizes, takes out doors and windows, and adds a margin for broken and cut bricks.
A standard UK and European brick is 215 × 102.5 × 65 mm. With a 10 mm mortar joint, each one covers 225 × 75 mm of wall face, so about 60 bricks make a square metre. US modular bricks are 7⅝ × 2¼ inches on the face, about 6.75 per square foot. Concrete blocks are much larger: about 10 per square metre, or 1.125 per square foot for US 8 × 16 inch blocks.
A single-skin (half-brick) wall is one brick thick, which is enough for a low garden wall. Taller walls and house walls are two skins, either solid or with a cavity, which doubles the count. Walls over about a metre need piers or a thicker build for strength, and higher walls need proper design.
Order 5 to 10% extra: some bricks break in transport, and cuts at ends and around openings waste part of others. Buy them all from one batch if you can, as the colour varies between batches.
Questions people ask
How many bricks are in a square metre?
About 60 standard 215 × 65 mm bricks for a single-skin wall with 10 mm mortar joints, and 120 for a double-skin wall.
How many bricks per square foot?
About 6.75 US modular bricks per square foot of wall, with 3/8 inch joints.
How many concrete blocks are in a square metre?
About 10 standard 440 × 215 mm blocks. US 8 × 16 inch blocks are about 1.125 per square foot.