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Brick Calculator

Brick Calculator

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

Brick Calculator

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

Use double wythe for thicker structural walls.

Results

Enter dimensions above to calculate

Brick Module & Wall Diagram

The "module" face size is the key to accurate brick counting. It includes the brick face plus the mortar joint on each edge, as shown.

MORTAR JOINT Brick Length (L) Brick Height (H)

Step-by-Step Formulas

1. Gross Wall Area

Gross Area = Wall Length × Wall Height

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

2. Subtract Openings

Net Area = Gross Area − Openings Area

Subtract windows, doors, and any other voids. Only count the face area that actually receives brickwork.

3. Count Bricks Using Module Size

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

Bricks are counted using the module face size: brick length + joint and brick height + joint. A double-wythe wall has two layers, roughly doubling the count.

4. Waste Allowance

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

Add 5–10% for a straightforward wall. Allow 10–15% for complex patterns, lots of cuts, corbelling, or tight colour matching.

5. Mortar Volume Estimate

Mortar per brick ≈ Module volume − Brick volume

An approximate mortar volume is estimated from the difference between the brick module size and the actual brick dimensions. Use it for rough ordering only — actual usage varies with joint tooling, cavities, and site conditions.

Common Brick Sizes by Region

Region / Type Length Height Width Joint
UK / Australian standard 215 65 102.5 10 mm
US modular (nominal 8×2⅔×4 in) 194 (7 5/8 in) 57 (2¼ in) 92 (3⅝ in) 9.5 mm (3/8 in)
US engineer 194 (7 5/8 in) 70 (2¾ in) 92 (3⅝ in) 9.5 mm (3/8 in)
Metric modular (Australia/NZ) 290 90 90 10 mm

* Dimensions are the actual (work size), not nominal. Always confirm with your supplier's product sheet.

Worked Example

A 6 m × 2.4 m wall with 1.8 m² of openings. UK standard brick (215 × 65 mm), 10 mm joint, single wythe, 10% waste.

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 (exact) = 12.60 ÷ 0.016875 ≈ 747 bricks
Order (10% waste) = ceil(747 × 1.10) = 822 bricks

💡 Pro tip

Always order bricks from the same production batch (kiln run) to avoid colour-lot variations. Most suppliers will calculate coverage using their own brick dimensions — compare their figure to yours as a sanity check.

Frequently Asked Questions

Do I need to include mortar joints in the brick size?
Yes. Brick counts are most accurate when using the brick module size (brick dimensions plus mortar joint thickness). The calculator includes joint thickness so estimates match real site layouts.
Should I subtract windows and doors?
Yes. Subtract the total openings area so you only count the face area of brickwork. Keep openings slightly conservative if unsure and rely on the waste allowance for small differences.
How much waste should I allow?
For straightforward walls, 5–10% is common. For complex patterns, lots of cuts, or tight colour matching, 10–15% is safer. Always round up to whole bricks.
What is a wythe in brickwork?
A wythe is a single-brick-thick vertical section of a wall. Single-wythe is one brick; double-wythe is two bricks (common for structural or cavity walls).

Assumptions & Reference Values

This tool returns estimates using the standard engineering formulas and the default waste/coverage/density/yield parameters shown in the calculator inputs and results. Always verify assumptions (material specs, site conditions, and local requirements) against your supplier data and project plans.

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