Brick Calculator

Brick Calculator online

Estimate how many bricks a wall needs from the wall area and the brick face dimensions — including the mortar-joint and breakage judgements that decide whether you run short or over-order.

How it works

The tool divides wall area by the face area of one brick, then adds the allowance: Bricks = Wall area / ((Length / 1000) × (Height / 1000)) × (1 + Allowance / 100). Length and height are converted from millimetres to metres before dividing. At the defaults, one brick face covers 0.200 × 0.060 = 0.012 m², so each square metre needs 1 / 0.012 = 83.33 bricks before allowance. The allowance field covers mortar joints, cuts, and breakage together — the tool does not subtract a separate joint width.

Worked example

A 10 m² garden wall with 200 × 60 mm bricks and 5% allowance: 10 / 0.012 = 833.33 bricks net, then 833.33 × 1.05 = 875 bricks to buy (round up). With 10% allowance for many corners or openings: 833.33 × 1.10 = 916.7, so 917 bricks. Deduct window and door areas from the wall area before entering it.

Units

Wall area is in square metres; brick dimensions are in millimetres, so 200 mm = 0.2 m. If you work in feet, convert first: 1 m² = 10.764 ft². A standard 10 mm mortar joint is already absorbed into the allowance — if your bricklayer uses unusually wide joints, raise the allowance rather than changing the brick size.

Practical tips

• Measure wall area as length × height minus openings; for a double-wythe (two-brick-thick) wall, double the single-layer count.
• Use 5% allowance for plain rectangular walls and 10–15% where there are piers, arches, or many cuts.
• Buy all bricks from one batch so colour stays consistent; keep 10–20 spares for future repairs.
• This is a quantity takeoff, not structural guidance — wall thickness, ties, lintels, and lateral support should be checked by a qualified professional.

Edge cases and limitations

• Joints are inside the allowance here. This calculator divides by the bare brick face (200 × 60 mm → 83.3 bricks/m²) and lets the waste percentage absorb the mortar joints. If you instead enter the laying module — brick plus one 10 mm joint, 210 × 70 mm → 68 bricks/m² — use little or no allowance. Applying both double-counts the joints and over-orders by about a fifth.
• Regional sizes differ. A UK standard brick is 215 × 65 mm face; a US modular brick is 194 × 57 mm. Enter the face of the brick you are actually buying — a few millimetres per brick compounds across a wall.
• Two skins, twice the bricks. A double-thickness or cavity wall needs both leaves counted (run the calculation per skin and add), plus wall ties, which this count does not include.
• Breakage is separate from cutting waste. Soft or reclaimed bricks can lose another 5% to transport and handling damage. Order the breakage allowance on top when the bricks are fragile or the site is rough.

Privacy and browser processing

The calculation runs entirely in your browser — your wall dimensions are never uploaded.

Frequently asked questions

How many 200 × 60 mm bricks cover one square metre?

83.33 before waste, since 1 / (0.2 × 0.06) = 83.33. With 5% allowance that becomes 83.33 × 1.05 = 87.5, so order 88 per square metre.

What allowance covers mortar joints?

For stretcher bond with 10 mm joints, 5–7% is typical on plain walls. On the 10 m² example, 5% gives 875 bricks while 10% gives 917 — the 42-brick difference covers extra cutting around openings.

Do I enter gross or net wall area?

Enter net area after subtracting doors and windows. A 12 m² wall with a 1.8 m² window should be entered as 10.2 m², giving 10.2 / 0.012 = 850 bricks net before allowance.

Does the result cover a double-thickness wall?

No, it counts one brick skin. A 10 m² double-wythe wall at 5% allowance needs 875 × 2 = 1,750 bricks, plus any pillars calculated separately.

Related tools