Brick & block calculator
Wall dimensions in, brick count out — with mortar volume, cement and sand, openings deducted and wastage added. Works with any brick or block size.
Units per m³ = 1 ÷ (nominal L × W × H)
Unit size — · — per m³ · mortar is —% of wall volume · dry mortar — m³ · sand — cft · gross area — m²
How this calculator works
Everything is done by volume, because area-based rules break the moment the wall thickness changes.
- Net wall area = length × height, minus the openings you enter.
- Wall volume = net area × thickness.
- Nominal unit size = the brick plus one mortar joint on each of its three dimensions. Units per m³ = 1 ÷ that nominal volume — which is where the familiar 500 bricks per m³ comes from for a 190 × 90 × 90 brick with 10 mm joints.
- Mortar volume = wall volume minus the volume the bricks themselves occupy, so it falls out of the geometry rather than a thumb rule.
- Dry mortar = wet mortar × 1.33, then split by the mix ratio into cement and sand.
Wastage is applied to the brick count only, after openings are deducted — applying it to the gross wall inflates the order with bricks that were never going to be laid.
Read the full guide: How Many Bricks in a Wall? The Formula, with Mortar and Wastage
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Every calculation a site needs — concrete, brick, steel, plaster, paint and more — in one app that works offline, in metric and imperial, anywhere in the world.
