Brick Calculator

How many bricks do I need?

The quick rule of thumb is 59 bricks per square metre of single-skin wall. That accounts for 10mm mortar joints on the bed and perpend. The calculator does the same maths but lets you adjust for different brick sizes, wall area, and wastage.

Standard UK brick sizes

A standard UK brick is 215 x 102.5 x 65mm. With a 10mm mortar joint all round, the working size becomes 225 x 112.5 x 75mm. Most house bricks you'll find at a builders' merchant follow this size, but it's worth measuring if you're matching existing brickwork.

What about mortar?

The calculator works out the mortar volume based on joint thickness and the number of bricks. For a standard 10mm joint, you'll need roughly 0.03 m³ of mortar per square metre of wall. That's the wet volume, so if you're mixing your own you'll want to apply a bulking factor to get the dry ingredients right. Our mortar mix calculator can help with that.

How is wastage calculated?

The default is 5%, which covers cuts, breakages, and the odd dropped brick. If you're doing fiddly work with lots of cuts (bay windows, curved walls), bump it up to 10%. For a straightforward straight run, 5% is usually plenty.