This works out how many bricks a wall needs, from the wall’s area and the number of bricks per square foot that a specific brick and mortar joint combination produces.
Why a brick’s face and its footprint on the wall aren’t the same size
A standard US modular brick is 3⅝ × 2¼ inches on its own face, but laid with a ⅜ inch mortar joint around it, it occupies roughly 8 × 2⅝ inches of wall including that joint — the mortar takes up real space that has to be counted. This calculator’s default of 7 bricks per square foot reflects the standard modular brick with a standard joint; both genuinely vary by product and region, so the figure is fully editable.
How to use this calculator
- Enter the total wall area.
- Subtract the area taken up by doors and windows.
- Check the bricks-per-square-foot figure against your specific brick and mortar joint, if it differs from the standard modular default.
Frequently asked questions
Why isn’t a brick’s own face size enough to calculate this?
Because the mortar joint around every brick adds real width and height to how much wall space each brick actually occupies — ignoring it would understate how many bricks a wall needs.
What if I’m using a different brick size than standard modular?
Adjust the bricks-per-square-foot figure to match — this depends on both the brick’s actual dimensions and the mortar joint width you’re using, both of which vary by product.
How much waste should I add for a real job?
The default 10% covers ordinary breakage and cutting waste for a straightforward wall — more complex work (lots of corners, cut bricks around openings) reasonably calls for a higher margin.
Does this work for concrete blocks too?
Yes — enter the appropriate blocks-per-square-foot figure for your specific block size and joint, since standard concrete masonry units are a different size from a modular brick.
Why do openings get subtracted before the brick count, not after?
Because a door or window is real wall area you aren’t laying brick across — subtracting it first means every brick counted is actually needed, rather than over-ordering and discovering the surplus only after the wall is built.
