The Brick Wall Calculator calculates how many bricks you need for a wall and roughly how much mortar goes between them.
Each brick covers its face size plus one mortar joint: (brick length + joint) × (brick height + joint). Divide the net wall area by that, multiply by the number of skins (one for a half-brick wall, two for a one-brick wall), and add waste. Mortar is estimated as the wall volume minus the volume of the bricks.
Brick Wall Calculator
Number of bricks and volume of mortar for a single- or double-skin brick wall, with openings and waste.
Formula
- Bricks per m² (one skin): 1 ÷ ((l + j) × (h + j))
- Bricks: (L × H − openings) × bricks per m² × skins × (1 + waste %)
- Mortar (approx.): wall volume − brick volume
Where l, h = brick length and height, j = mortar joint, L and H = wall length and height.
How the Calculation Works
Step 1: Add the joint to the brick length and height to get the area each brick occupies on the wall face.
Step 2: Divide the net wall area by that and multiply by the number of skins.
Step 3: Add waste, and estimate mortar from the space not taken by bricks.
Variables Explained
| Input | Meaning |
|---|---|
| Brick length, height, depth | Actual brick size, e.g. 215 × 65 × 102.5 mm |
| Mortar joint | Joint thickness, e.g. 10 mm |
| Wall thickness | Single skin (half brick) or double skin (one brick) |
Example Calculation
Given: wall 5 m × 2 m, 215 × 65 mm bricks, 10 mm joints, single skin, 5% waste
Area per brick: 0.225 × 0.075 = 0.016875 m² → about 59.3 bricks per m²
Bricks: 10 m² × 59.26 × 1.05 ≈ 622.2
Result: 623 bricks; mortar ≈ 0.18 m³
Common Brick Sizes
| Brick | Size | Bricks per m² (10 mm joints, one skin) |
|---|---|---|
| UK standard | 215 × 102.5 × 65 mm | ≈ 59.3 |
| US modular | 7⅝ × 3⅝ × 2¼ in (194 × 92 × 57 mm) | ≈ 73 |
Brick sizes vary by region and manufacturer — enter the actual size of the brick you buy.
Material Estimation Notes
The mortar estimate leaves out frogs (indentations) in bricks, the collar joint between skins and mortar waste, which can add noticeably. Mortar is often bought as dry bags or mixed from sand and cement; the bag label or mix ratio tells you how much each produces.
Waste Factor Considerations
Cuts at corners, openings and ends, plus breakage in delivery, add waste. Walls with many openings or decorative bonds need more.
Frequently Asked Questions
How many bricks are in 1 m²?
About 59–60 standard 215 × 65 mm bricks per skin with 10 mm joints.
How do you calculate bricks for a wall?
Wall area × bricks per square meter × number of skins, plus waste.
How much mortar do I need for 1,000 bricks?
It depends on the joint size, brick frogs and waste; use the calculator’s estimate as a starting point.
What is the difference between single and double skin?
A single-skin (half-brick) wall is one brick deep; a double-skin (one-brick) wall is two bricks deep and needs twice as many.
Should I subtract windows and doors?
Yes — enter their total area as openings.