About the Brick Calculator
Ordering bricks by guesswork leads to shortages or large leftovers. This calculator takes the area of the wall, subtracts nothing you have not already taken off, and gives the number of bricks including a waste allowance. It uses the real size of a brick plus the mortar joint, for the standard UK brick or the US modular brick, in metric or imperial areas. Type the wall area, the brick size and the waste allowance and the bricks needed appears at once, with a few related figures underneath, and you can copy the result with one tap. The sums run in your browser, so nothing you enter is uploaded.
Updated October 2026
How to use the Brick Calculator
- 1Enter the wall area, the brick size and the waste allowance.
- 2Pick the units or options from the menus if the bricks needed tool offers them.
- 3Read the bricks needed in the large result box.
- 4Look at the extra rows for related figures.
- 5Press Copy result to keep the answer.
When you need the bricks needed
Builders and home owners use it to order bricks for garden walls, extensions, barbecues and repairs, and to compare the cost of different brick sizes. Knowing the count also helps to estimate the mortar and the weight to be delivered.
A single skin wall laid flat uses the figures here. A double-thickness wall needs twice as many. Remember to take off the area of doors and windows, and add extra for cuts around corners and openings.
How the bricks needed is worked out
Bricks per square metre = 1 ÷ ((brick length + joint) × (brick height + joint)). Total = bricks per m² × area × (1 + waste). A standard UK brick, 215 × 65 mm with a 10 mm joint, needs 59.26 bricks per square metre. A 20 m² wall needs 1,185 bricks, and with 5 percent waste, 1,245. For a US modular brick the figure is about 6.86 per square foot, or 73.8 per square metre.
Every answer on this page comes from that one rule, so you can check any result by hand with a calculator. The figures shown underneath, such as other units, are conversions of the same answer.
- UK and US brick sizes
- Metric or imperial area
- Waste allowance included
Mistakes to avoid with bricks needed
Bricks are often sold in packs, so round up to a full pack. The count does not include special bricks, such as copings or lintels. Small differences between brands in size also change the result, so check the actual dimensions of your brick.
On phone and computer
On a phone, type into the boxes one after another and read the bricks needed underneath; Copy result puts it on the clipboard for a message or a note. On a computer the inputs sit on the left and the answer on the right, so you can change one figure and watch the bricks needed move. The brick calculator works the same on both. Brickwork rarely stands alone. Plan the base with Concrete Calculator and Gravel Calculator, find the wall area with Area Calculator, and use Tile Calculator if the same job includes a floor.
Features
- Single skin only
- Subtract openings
- Round up to full packs
- Clear messages when the bricks needed inputs make no sense
- Copy the result with one tap
- Private: nothing is uploaded
Frequently asked questions
How do I calculate bricks needed?
Bricks per square metre = 1 ÷ ((brick length + joint) × (brick height + joint)). Total = bricks per m² × area × (1 + waste). A standard UK brick, 215 × 65 mm with a 10 mm joint, needs 59.26 bricks per square metre. A 20 m² wall needs 1,185 bricks, and with 5 percent waste, 1,245. For a US modular brick the figure is about 6.86 per square foot, or 73.8 per square metre.
What is the formula for bricks needed?
Bricks per square metre = 1 ÷ ((brick length + joint) × (brick height + joint)). Total = bricks per m² × area × (1 + waste). The brick calculator applies it exactly and rounds only the displayed answer to six significant figures.
How many bricks per square metre?
About 59 for a standard UK brick with a 10 mm joint, in a single-skin wall laid as stretchers.
How much waste should I allow?
5 percent for simple walls and 10 percent for complex ones with many cuts.
How much mortar do I need?
It depends on the joint thickness and the brick, so ask your supplier for a figure; many sell mortar by the number of bricks it will lay.
Is this brick calculator free and private?
Yes. It is free, needs no account and runs in your browser, so the numbers you type are not uploaded or stored.