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.

Wall area (m²)Wall typeBricks per m² (check dimensions/bond)Waste allowance (%)

Result

Bricks required

How to use this tool

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

The 215 × 102.5 × 65mm unit and 10mm mortar joint are calculation assumptions, not universal brick specifications.
Area already excludes large openings such as doors and windows; small openings are absorbed by the waste allowance.

Sources & reference data

Brick Development Association — UK brick industry body (brick formats and guidance)

Technical details: what the fields mean

Wall area wallAreaM2: Total wall area, in square metres (length × height, minus large openings).
Wall type wallType: Single or double skin multiplies the editable per-skin rate (default 60 bricks/m²) by one or two. The default assumes the nominal brick and joint dimensions below; verify actual units and bond with your plans or supplier.
Bricks per m² (check dimensions/bond) bricksPerM2: Bricks per square metre for one skin. The 60 default is an illustrative estimate based on nominal dimensions and bond; edit it for the specified brick and layout.
Waste allowance wastePercent: Extra bricks to cover breakages and cut bricks at corners/openings.

Methodology

Estimated count = wall area × editable per-skin rate × skin count × (1 + editable waste%). The illustrative 60/m² rate assumes a 215 × 102.5 × 65mm brick, 10mm joints and stretcher bond. Area is geometric; count depends on the entered unit rate, bond, actual units, openings and waste. Confirm dimensions and bond against project and supplier data.

Worked example

20m² single-skin wall, nominal 215 × 102.5 × 65mm bricks, 10mm joints and stretcher bond, 5% waste

Inputs: Wall area: 20 m², Wall type: single, Bricks per m² (check dimensions/bond): 60, Waste allowance: 5%

Result: 1,260 bricks required

Same 20m² wall built as a double-skin (two leaves of facing brick), 5% waste — the single vs double comparison

Inputs: Wall area: 20 m², Wall type: double, Bricks per m² (check dimensions/bond): 60, Waste allowance: 5%

Result: 2,520 bricks required — exactly twice the single-skin figure. If the inner leaf is blockwork rather than brick, use single-skin here and the block calculator for the inner leaf.

Where the 60/m² default comes from

Inputs: Brick face 215 × 65mm plus a 10mm joint on each = 225 × 75mm per brick

Result: 1 ÷ (0.225m × 0.075m) = 1 ÷ 0.016875m² ≈ 59.3 bricks/m², rounded up to 60. Larger-format or imperial-size reclaimed bricks change this, so recalculate with their real face size.

Practical guidance

Order from the same batch/kiln run where possible — brick colour can vary noticeably between batches.
Merchants usually sell bricks by the pack, not individually — round the result up to whole packs using the pack size on your supplier's listing, and ask whether part-packs can be returned.
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?

The default is 60 per m² for one skin, doubled for two, assuming the stated brick dimensions, 10mm joints and stretcher bond. Edit the rate for your actual brick and layout.

How much waste allowance should I add for bricks?

Waste depends on wall shape, openings, bond and cuts. The 5% default is illustrative and editable; choose an allowance for the job and confirm with your supplier.

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.

Last reviewed: 2026-10-11

Assumes standard brick dimensions and mortar joints — non-standard or reclaimed bricks will need a different bricks-per-m² figure.

This tool provides an indicative estimate, based on the assumptions stated above.

Theme and tool preferences, along with saved and recently used lists, are stored only in this browser.