Bricks or blocks, mortar and wastage for a wall

Units needed units
Net wall area
Mortar volume (rough)
Assumption: single-skin wall with 10 mm joints — about 60 bricks or 10 blocks per m². Mortar is a rough estimate of 0.022 m³/m² for bricks and 0.011 m³/m² for blocks.

About Brick & Block Calculator

The brick and block calculator estimates how many masonry units a wall needs. Enter the wall length and height, choose between standard bricks (215 × 102.5 × 65 mm, about 60 per m²) and concrete blocks (440 × 215 × 100 mm, about 10 per m²), subtract openings, and add a wastage percentage for cuts and breakage.

The math assumes a single-skin wall with 10 mm mortar joints — the standard coursing that produces those 60-per-m² and 10-per-m² coverage figures. Alongside the unit count you get the net wall area and a rough mortar volume, estimated at 0.022 m³ per m² for brickwork and 0.011 m³ per m² for blockwork.

It is the quick way to answer “how many bricks do I need” before ordering — for a garden wall, an extension skin, or a blockwork partition — free and instant in your browser. Quantities are estimates: cavity walls, different bonds, and local practice change the numbers, so order with your supplier’s guidance.

How to use Brick & Block Calculator

  1. Enter the wall length and height in meters.
  2. Choose the masonry unit: standard brick or concrete block.
  3. Enter the total area of openings — doors and windows — to subtract, in m².
  4. Set a wastage percentage for cutting and breakage.
  5. Read the units needed, the net wall area, and the rough mortar volume.

Frequently asked questions

About 60 standard bricks (215 × 102.5 × 65 mm) per m² in a single-skin stretcher-bond wall with 10 mm joints. Concrete blocks at 440 × 215 mm cover the same area with about 10 units.

A 5% allowance is common for straightforward walls; go to 10% where there are many cuts, piers, or openings, or when handling seconds. The wastage field applies the percentage on top of the net count.

Roughly 0.022 m³ of mortar per m² of single-skin brickwork and about half that — 0.011 m³/m² — for blockwork, since blocks have far fewer joints. These are rough figures; the mix and joint tooling affect real usage.

It computes one skin at a time. For a cavity wall, run the calculation once per leaf — for example bricks for the outer skin, then blocks for the inner — and order wall ties and insulation separately.

Good enough for ordering with a sensible margin, but real usage varies with bond pattern, joint thickness, and site practice. Treat the output as an estimate and confirm quantities against your drawings and local building requirements.

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