Brick Calculator (Number of Bricks)

🧱 Brick Calculator

Number of bricks and mortar for a wall, with openings and wastage.

Wall length (m)

Wall height (m)

Openings to deduct (m²)

Wall type

Wastage (%)

Bricks Needed

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Net Wall Area

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Mortar (≈)

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Incl. Wastage

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⚠️ Based on standard 215×102.5×65 mm bricks with 10 mm joints (≈57/m² half-brick, 114/m² one-brick). Adjust the per-m² figure for other brick/block sizes. Mortar volume is indicative. Verify before professional use.

Standards & method

✓ Independently verified 12 July 2026

Basis

First principles

Method

Geometric take-off. Brick and mortar-joint dimensions vary by region and standard (e.g. BS EN 771, ASTM C216) — confirm the actual unit size with the supplier.

Core formula

bricks = wall area / (brick face area INCLUDING mortar joint) × (1 + wastage)

Why this matters

Quantity take-offs are geometry plus a wastage allowance — typically 5–10%, more for cuts and complex shapes. Ordering the bare geometric quantity guarantees a shortfall. Always confirm the actual unit dimensions with the supplier; nominal sizes vary by region.

Independently verified

12 July 2026 — Formula re-derived from first principles and verified numerically against hand-computed reference cases, including edge cases and unit handling.

Results are for guidance. Verify against the current edition of the governing standard and have a qualified professional review before use in practice.

Brick Quantity — Method

Brick counts are estimated per square metre of wall face. A standard 215 x 102.5 x 65 mm brick with 10 mm mortar joints gives about 57 bricks per square metre for a single-leaf (half-brick) wall and about 114 per square metre for a one-brick (double-leaf) wall. Multiply the net wall area (gross area minus door and window openings) by the per-square-metre figure, then add a wastage allowance (around 5%) for cuts and breakage. Mortar volume is roughly 0.02 to 0.05 cubic metres per square metre depending on wall thickness and joint size.

Frequently Asked Questions

How many bricks do I need per square metre?⌄

For standard UK/metric bricks with 10 mm joints, about 57 per square metre for a half-brick (single-leaf) wall and about 114 per square metre for a one-brick (double-leaf) wall.

How do I calculate bricks for a wall?⌄

Multiply the net wall area (length x height minus openings) by the bricks per square metre for the wall type, then add about 5% for wastage. A 25 m2 half-brick wall is about 25 x 57 x 1.05 = 1500 bricks.

Should I deduct doors and windows?⌄

Yes, subtract the area of openings from the gross wall area before applying the per-square-metre figure, otherwise you over-order significantly on walls with large openings.

How much wastage should I allow?⌄

Around 5% for normal brickwork to cover cuts, breakage and the odd reject; allow more (up to 10%) for complex shapes, lots of cutting or reclaimed bricks.

Does brick size change the count?⌄

Yes. The 57/114 figures are for standard bricks. Larger format or metric modular bricks and blocks cover more area each, so recalculate the per-square-metre figure from the actual brick face plus joint.

Estimating Brick Quantities

Estimating brickwork is an area calculation. Because every brick plus its mortar joint occupies a known face area, the number per square metre is fixed for a given brick size and bond, and the job becomes measuring the wall.

The method

Net wall area (minus openings) x bricks per square metre x wastage. Single-leaf walls use about 57/m2, double-leaf about 114/m2 for standard bricks with 10 mm joints.

Mortar and ordering

Mortar is roughly 0.02-0.05 m3 per m2 of wall. Always order a little over the calculated figure for cuts and breakage. For the mortar mix and any concrete, use the concrete calculator.

Related: Concrete Mix, Paint Quantity.

Brick Calculator

Brick quantity — Quick answer