How it's calculated
Wall volume = L × H × T
Bricks = Wall volume ÷ Volume per brick (incl. 10mm joint)
Mortar = Wall volume × 30% (typical joint allowance)
For a 1:6 cement-sand mortar, dry mortar = wet mortar × 1.30. Cement weight is then dry mortar × (1 ÷ 7) × 1,440 kg/m³, divided by 50 kg per bag.
Standard sizes
| Type | Brick size | Including 10mm joint | Bricks per m³ |
|---|---|---|---|
| Modular (IS) | 190 × 90 × 90 mm | 200 × 100 × 100 mm | 500 |
| Standard / imperial | 230 × 110 × 75 mm | 240 × 120 × 85 mm | ~460 |
FAQ
What thickness should I use?
For modular bricks: 0.10 m (half brick), 0.20 m (one brick) or 0.30 m (one-and-half brick). For imperial: 0.115 m, 0.23 m or 0.345 m respectively. Half-brick walls are partition-only; load-bearing walls should be at least one brick thick.
What's a typical waste allowance?
5% on small jobs is standard for breakage and cutting losses. On long, straight walls with experienced masons, 3% suffices. Add more (8–10%) for jobs with lots of cuts and corners.
Why does my supplier quote a different number?
Suppliers sometimes quote bricks per cubic metre of brickwork (~500) and sometimes per cubic metre of bricks (without joint, ~610). Check which they mean before ordering.