How to use the brick calculator
- Enter the wall length and height. For several walls, add their lengths together if they are the same height.
- Enter the total area of doors and windows to subtract.
- Choose the wall thickness: half brick (single skin), one brick (double) or 1½ brick.
- Pick your brick size or enter a custom size and joint thickness.
- Keep 5% extra for breakage and choose your mortar mix to get cement and sand.
Brick calculation formula
Net wall area = Length × Height − Openings Bricks = Net area × Number of skins ÷ [(Brick length + joint) × (Brick height + joint)] Bricks to buy = Bricks × (1 + extra %) → round up
This face-area method counts exactly how many brick faces fit in the wall including one mortar joint each, so it works for any bond (stretcher, English or Flemish). For a one-brick wall, the headers and the two skins of stretchers both give the same count per square metre.
Worked example (India)
A 10 m long, 3 m high half-brick wall of modular bricks (190 × 90 × 90 mm, 10 mm joints):
- Area = 10 × 3 = 30 m²
- Brick face with joint = 0.20 × 0.10 = 0.02 m² → 30 ÷ 0.02 = 1,500 bricks
- With 5% extra = 1,575 bricks
- Mortar = 30 × 0.09 − 1,500 × (0.19 × 0.09 × 0.09) = 0.39 m³ wet → 0.52 m³ dry
- 1:6 mortar → 107 kg cement (2.14 bags) and 0.45 m³ sand (15.8 CFT)
Bricks per square metre / square foot
| Brick | Joint | Half-brick wall | One-brick wall |
|---|---|---|---|
| India modular 190 × 90 × 90 mm | 10 mm | 50 / m² | 100 / m² |
| India traditional 230 × 115 × 75 mm | 10 mm | 49 / m² | 98 / m² |
| UK 215 × 102.5 × 65 mm | 10 mm | 59.3 / m² | 118.5 / m² |
| US modular 7⅝ × 3⅝ × 2¼ in | ⅜ in | 6.75 / ft² | 13.5 / ft² |
Thicker mortar joints mean fewer bricks but more mortar. If your mason uses 12–15 mm joints, choose “Custom size” and enter the real joint thickness for an accurate count.
Tips for ordering bricks
- Soak clay bricks before laying (in hot climates) so they don't suck water out of the mortar.
- Buy from one batch. Colour varies between kiln runs, which shows on face brickwork.
- Mortar strength: 1:6 is usual for non-load-bearing brick walls, 1:4 for load-bearing walls and 1:3 for exposed or below-ground work.
- Pallets: bricks are often sold in thousands or pallets of 400–500; round your order to suit and keep a few spare for repairs.