How to use this calculator
- Enter the wall's length and height, and take off doors and windows.
- Choose single or double skin.
- Pick your brick or block, or enter a custom size with its joint.
The formula
Units per m² = 1 ÷ ((length + head joint) × (height + bed joint))
Units = units per m² × wall area × skins × (1 + extra %), rounded up
Mortar ≈ wall area × skins × depth × (1 − face area ÷ (face area with joints))
A UK brick (215 × 65 mm) with 10 mm joints takes 225 × 75 mm of wall, which is 59.3 bricks per m² — the trade's "60 a metre". A 440 × 215 mm block is 9.9 per m², so "10 a metre".
A US modular brick with 3/8 in joints is 6.86 bricks per ft², and a standard CMU block is 1.125 per ft².
Worked example
A 5 m × 2 m single-skin wall is 10 m². UK bricks with 10 mm joints need 59.26 per m².
With 5% extra, buy 623 bricks. Mortar: about 185 L.
Tips before you buy
- Buy bricks from one batch, and mix bricks from several packs as you lay to avoid colour bands.
- Keep bricks and blocks off the ground and covered before use.
- Wear gloves and eye protection when cutting bricks or handling cement.
Frequently asked questions
›How many bricks per square metre?
About 60 for UK standard bricks in a single-skin wall, and 120 for a double-skin (one-brick) wall.
›How many blocks per square metre?
About 10 standard 440 × 215 mm blocks.
›How many bricks per square foot?
About 6.9 US modular bricks with 3/8 in joints.
Sources
- Standard sizes: UK brick 215 × 102.5 × 65 mm and block 440 × 215 mm with 10 mm joints; US modular brick and CMU with 3/8 in joints.
Formulas last reviewed: September 29, 2026. How we check our formulas