Do I need to include mortar joints in the brick size?

Yes. Brick counts are most accurate when calculated using the brick module size (brick dimensions plus the mortar joint thickness). This calculator includes joint thickness directly so the estimate matches typical site layouts.

Should I subtract windows and doors?

Yes. Subtract the total openings area so you only count the face area that will be laid in brick. Keep openings slightly conservative if you are unsure and rely on the waste allowance to cover small differences.

How much waste should I allow?

For straightforward walls, 5–10% waste is common. For complex patterns, lots of cuts, or tight colour matching, 10–15% is safer. Always round up to whole bricks/bundles as sold by your supplier.

Brick Calculator (Bricks + Mortar Allowance)

Brick Calculator

Estimate how many bricks you need for a wall by using net wall area (after openings), your brick size, mortar joint thickness, wall thickness (single/double wythe), and a practical waste allowance.

Brick Calculator

Estimate bricks for a wall (with openings), plus a practical mortar allowance

Wall thickness

Use double wythe for thicker structural walls.

Waste allowance

Wall length

Wall height

Openings area

Brick length

Brick height

Brick width

Joint thickness

Results

Enter dimensions above to calculate

Formulas used

Brick counts depend on the brick “module” size, meaning the brick face plus mortar joint thickness.

1. Wall Area

Formula:

Gross Area = Length × Height

Measure the full wall face first. Use the same unit system for both dimensions so the area is consistent (m² or ft²).

2. Subtract Openings

Formula:

Net Area = Gross Area − Openings Area

Subtract windows, doors, and other openings so you only count the area that actually needs brickwork.

3. Bricks per Area (Module Size)

Formula:

Bricks = Net Area ÷ ( (L + J) × (H + J) ) × Wythes

Bricks are counted using the brick “module” face size, which includes the mortar joint thickness (J). A double-wythe wall has two layers of bricks, so it roughly doubles the brick count.

4. Waste Allowance

Formula:

Order Bricks = ceil(Bricks × (1 + Waste%))

Add waste for cuts, breakage, and colour matching. 5–10% is common for simple walls; 10–15% is typical if there are lots of cuts or details.

Example

A 6 m × 2.4 m wall with 1.8 m² of openings, using a 215 × 65 mm brick and 10 mm joints (single wythe).

Gross area = 6 × 2.4 = 14.40 m²
Net area = 14.40 − 1.80 = 12.60 m²
Module face = (0.215 + 0.010) × (0.065 + 0.010) = 0.016875 m²
Bricks ≈ 12.60 ÷ 0.016875 = 747 bricks
Order (10% waste) = ceil(747 × 1.10) = 822 bricks

Frequently Asked Questions

Do I need to include mortar joints in the brick size?: Yes. Brick counts are most accurate when calculated using the brick module size (brick dimensions plus the mortar joint thickness). This calculator includes joint thickness directly so the estimate matches typical site layouts.
Should I subtract windows and doors?: Yes. Subtract the total openings area so you only count the face area that will be laid in brick. Keep openings slightly conservative if you are unsure and rely on the waste allowance to cover small differences.
How much waste should I allow?: For straightforward walls, 5–10% waste is common. For complex patterns, lots of cuts, or tight colour matching, 10–15% is safer. Always round up to whole bricks/bundles as sold by your supplier.