Brick and Mortar Calculator
Calculate how many bricks and how much mortar you need for any wall, path, or project.
Supports metric and imperial sizes.
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:
| Standard | Brick Dimensions (L × H × W) | Mortar Joint |
|---|---|---|
| US Standard | 203 × 57 × 95 mm (8" × 2¼" × 3¾") | 10 mm (⅜") |
| UK Standard | 215 × 65 × 102.5 mm | 10 mm |
| Australian | 230 × 76 × 110 mm | 10 mm |
| Metric Modular | 190 × 57 × 90 mm | 10 mm |
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)
- US bricks: Approximately 45–55 kg per m²
- Typical mortar mix: 1 part cement : 3–4 parts sand (by volume)
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.