Building materials calculators

Work out exactly how much you need for the job — then tap through to find the merchants near you, closest first. Free, no signup.

Brick calculator — how many bricks per m²?

A single-skin wall needs ~60 bricks/m², a double-skin ~120. Enter your wall area:

Concrete block calculator

Standard 440×215mm blocks work out at ~10 per m² of wall.

Concrete calculator — how much concrete do I need?

Enter your slab or footing dimensions for the volume plus bag estimates.

Paint calculator — how much paint do I need?

Based on surface area, number of coats and coverage per litre.

Plasterboard calculator

Sheets needed for a wall or ceiling area (standard board is 2.4m × 1.2m).

Tile calculator

Tiles needed for a floor or wall, including a cutting allowance.

Decking calculator

Boards needed for your deck, accounting for the gap between boards.

All results are estimates with a wastage allowance built in — always double-check quantities before ordering, especially for footings and structural work.