Brick calculator
The brick face plus the joint decides how many fit per square metre.
Your inputs
Your inputs are processed on your device and are not sent to a server.
Example loaded. You can change any value.
There is no figure yet: nothing is calculated until you ask for it.
- Enter your measurements.
- Check the units and the assumptions.
- Press Calculate, or load the example.
Rather see a worked case? Press “Load example” and change any value afterwards.
Next step
The units are counted; what is left is the mortar that fills the joints.
Where each number comes from Conversion constants are exact; densities and coverage rates come from cited sources; everything else is an assumption you can change. Methodology · Sources and updates
How to use it
- Measure the wall area.
- Enter the size of the visible face of the brick.
- Adjust the mortar joint: it changes the count noticeably.
- Subtract the area of any openings.
How it is calculated
Bricks per square metre depend not on the brick alone but on the brick plus the joint:
A standard UK brick of 215 x 65 mm with a 10 mm joint occupies a module of 225 x 75 mm = 0.0169 m², giving 59.3 bricks per square metre. Ignoring the joint would give 71.6: a 20 % error, which on a 20 m² wall is 245 bricks too many.
The figure is for one leaf, that is, a single unit thickness. A double-leaf wall needs twice as many.
Worked example
A 108 sq ft wall in 8 x 2.25 in brick, 3/8 in joint, 5 % breakage:
- Module: 8.375 x 2.625 in = 0.01418 m²
- Bricks per m²: 70.5 (6.55 per sq ft)
- Without waste: 10 m² x 70.5 = 705 bricks
- With 5 % breakage: 741 bricks
Good to know
- Measure a real brick. Nominal and actual sizes differ, and vary by country and maker. Measure the one you are buying.
- Face or on edge. The same brick laid flat or on edge shows a different face and completely changes the count per square metre.
- Breakage. 5 % is normal for common brick. For facing brick, where a chipped corner is a reject, use 10 %.
- The wall needs mortar too. From the result you can move to the mortar calculator with the same measurements.
Frequently asked questions
How many bricks per square foot?
With an 8 x 2.25 in brick and a 3/8 in joint, about 6.55 bricks per square foot for a single leaf. A standard UK brick (215 x 65 mm, 10 mm joint) gives 59.3 per square metre, or 5.5 per square foot.
Does the mortar joint change the result much?
Yes. Going from 10 to 15 mm reduces bricks per square metre by about 5 %. Ignoring the joint entirely inflates the count by up to 20 %.
How many bricks for a double-leaf wall?
Twice what this calculator gives. The result is for one leaf, meaning a single brick thickness.
How much breakage should I allow?
5 % for common brick that will be rendered. 10 % for facing brick, where any chip makes a brick unusable, and a little more if there are many cut bricks.