Brick quantity calculator
Estimate how many bricks you need for a wall from its area, so you can order enough (with a sensible waste allowance) without a mid-job trip back to the merchant.
Result
Bricks required
Result
Wall area achievable
How to use this calculator
- Measure the wall's length and height and multiply them to get the area, or measure the area directly.
- Enter the area and choose single-skin or double-skin (cavity) wall.
- Read the number of bricks to order.
Assumptions
- Standard UK brick size with 10mm mortar joints.
- Area already excludes large openings such as doors and windows; small openings are absorbed by the waste allowance.
Technical details: what the fields mean
- Wall area
wallAreaM2 - Total wall area, in square metres (length × height, minus large openings).
- Wall type
wallType - Single = one skin of standard bricks (~60/m²). Double = a cavity wall with two skins (~120/m²).
- Waste allowance
wastePercent - Extra bricks to cover breakages and cut bricks at corners/openings.
Methodology
Bricks = area × bricks-per-m² × (1 + waste%). The 60/m² (single) and 120/m² (double) figures assume a standard UK brick (215 × 102.5 × 65mm) laid with 10mm mortar joints in stretcher bond.
Worked example
20m² single-skin wall, 5% waste
Inputs: wallAreaM2=20, wallType=single, wastePercent=5
Result: 1,260 bricks required
Practical guidance
- Order from the same batch/kiln run where possible — brick colour can vary noticeably between batches.
- Add a higher waste allowance (10–15%) for a wall with lots of corners, arches or cut bricks.
Common mistakes
- Forgetting to subtract large door/window openings from the area before entering it.
- Using single-skin figures for a cavity wall, which undercounts by half.
FAQs
How many bricks do I need per square metre?
About 60 for a standard single-skin wall, or 120 for a double-skin cavity wall.
How much waste allowance should I add for bricks?
5% suits a simple rectangular wall; use 10–15% if there are lots of corners or cut bricks.
I have a fixed number of bricks — how much wall can I build?
Use reverse mode below: enter your brick count and wall type to get the achievable area.