Brick and Mortar Calculator

Accurately estimating bricks and mortar before starting a project saves money, reduces waste, and keeps your project on schedule. Over-ordering ties up cash; under-ordering causes costly delays when you need to source matching bricks from the same batch.

Standard Brick Sizes

Brick sizes vary by country and type:

Calculating Brick Count

The number of bricks per square metre (or square foot) depends on the brick size and mortar joint:

Bricks per m² = 1,000,000 ÷ [(L + mortar) × (H + mortar)]

For a single-wythe (single brick thick) wall with UK bricks and 10mm joints:

• (215+10) × (65+10) = 225 × 75 = 16,875 mm² per brick face
• 1,000,000 ÷ 16,875 ≈ 59 bricks per m²

For US bricks: (203+10) × (57+10) = 213 × 67 = 14,271 → ≈70 bricks per m²

Mortar Quantity

Mortar volume depends on joint size and brick dimensions. A rule of thumb for typical wall construction:

• UK bricks: Approximately 50–60 kg of mortar per m² of wall (single wythe), and the calculator uses 55
• US bricks: Approximately 45–55 kg per m², calculator uses 50
• Australian bricks: Approximately 55–65 kg per m², calculator uses 60. A 110 mm wythe is thicker than the UK 102.5, so each joint holds more
• Typical mortar mix: 1 part cement : 3–4 parts sand (by volume). The breakdown below assumes 1:4, which works out near 20% cement by weight

Waste Allowance

Always add a waste factor of at least 5–10% for breakage, cuts, and mortar excess. In complex patterns (herringbone, diagonal) or around many openings, add 10–15%.

Multiple Wythes

A double-wythe wall (two bricks thick) requires approximately twice the bricks and mortar, plus ties between layers.