Brick Calculator
Bricks or blocks for a wall — the area is worked out for you, with doors, windows and other openings deducted.
About this calculator
UK bricklaying has settled maths: a standard 215×102.5×65mm brick with 10mm joints gives 60 bricks per square metre in a single-skin wall, and a 440×215mm concrete block gives 10 per square metre. Enter the wall dimensions, pick the material, and get the quantity with waste included.
The wall area is calculated for you — tell it how many door and window openings the wall has (plus any custom opening area for gates, arches or vents) and they're deducted automatically, so you order bricks for the wall you'll actually build, not for the holes in it.
The formula
Worked example
A garden wall 6m × 1.8m with one gate opening of 1.7 m², single skin, 5% waste:
- Gross area = 10.8 m²; net area = 10.8 − 1.7 = 9.1 m²
- Bricks = 9.1 × 60 × 1.05 ≈ 574 bricks
Common mistakes
- Counting an opening's bricks anyway by entering the gross wall size and no openings.
- Ordering exactly — cuts, breakages and rejects need the waste margin.
- Forgetting the lintel over every opening, which must be ordered separately.
- Ignoring the foundation: garden walls need a proper concrete footing sized to the wall.
Frequently asked questions
Assumptions & limitations
Standard UK brick/block sizes with 10mm mortar joints; door openings deducted at 1.9 m² and windows at 1.4 m² (use "other openings" for non-standard sizes). Lintels excluded. Structural walls need building-regulations compliance.
Sources & verification
- Brick Development Association — Industry guidance; ~60 bricks/m² in a half-brick wall with standard UK brick format (215×102.5×65 mm) and 10 mm joints
All sources last accessed 24 July 2026.
Spotted an error or an out-of-date figure? Report it — corrections are prioritised over all other work (see our corrections policy).