Brick & Block Calculator

It counts the bricks or blocks needed for a wall from its area, and estimates the mortar (cement and sand) to lay them. Enter the wall dimensions, deduct any openings, choose a single or double skin, and it returns the unit count including a waste allowance.

It depends on the unit size and joint. For a standard 8¾ × 2⅞ in (222 × 73 mm) brick face with ⅜ in (10 mm) joints there are about 4.7 bricks per square foot (50–52 per m²) in a single skin; a standard 15⅜ × 7½ in (390 × 190 mm) block works out at roughly 1.2 per square foot (12.5 per m²). The calculator computes it from the exact face size and joint you enter.

Multiply the wall length by its height for the area, subtract the area of any doors and windows, then multiply by the bricks per square foot — and by two for a double-skin (one-brick) wall. The calculator does this and adds your waste percentage on top.

A single skin (half-brick) wall is one brick thick and uses one layer of bricks per square metre — common for boundary walls and internal partitions. A double skin (one-brick) wall is two leaves thick for strength or load-bearing work, so it needs twice the bricks. Pick the one that matches your wall.

The calculator estimates the mortar volume from the joint size and wall thickness, then splits it into cement bags and sand for your chosen mix (1:3 strong, 1:4 general or 1:6 lean). Treat it as a guide — real usage varies with joint thickness, unit texture and wastage, so keep a little spare.

Around 5% for plain block walls with few cuts, and up to 10% for face brick or walls with lots of openings and corners, where cutting and breakage are higher. The calculator adds your chosen percentage so the delivered quantity covers the offcuts.