Brick and block calculator
The calculator needs JavaScript. The worked example, formula and figures below show exactly how it works, so you can do the sum yourself. A guide, not advice. Check your supplier's or maker's figures before ordering.
Short answer
Work out how many bricks or blocks a wall needs, less openings, for one or two skins. Enter your measurements below; every figure we start from is shown and you can change it.
Worked example
| You enter | Value |
|---|---|
| Wall | Wall: rectangle 5 m × 2 m |
| Unit | Brick |
| Face length | 215 mm |
| Face height | 65 mm |
| Joint | 10 mm |
| Wall thickness | Single skin (half-brick) |
| Waste allowance | 5% |
Order: 623 units
| Result | Value |
|---|---|
| Bricks or blocks | 623 |
| Per m² (one skin) | 59.26 |
| Wall area (after openings) | 10 m² |
Show the working
- Area: Wall 10 m² = 10 m²
- Per m²: 1 ÷ ((0.215 + 0.01) × (0.065 + 0.01)) = 59.26
- Count: 10 × 59.26 × 1 skin × 1.05 (5% waste) = 622.22, rounded up to 623
How it works
- Per m² = 1 ÷ ((face length + joint) × (face height + joint)), in metres
- Count = net wall area × per m² × skins × (1 + waste), rounded up
Two skins doubles the count (for example a one-brick wall or a cavity wall's two leaves).
Our default (adjustable)
These are typical planning figures and our own allowances, not facts about your product. Change any of them in the calculator to match your bag, pack or tin.
| Figure | Our default (adjustable) | Kind | Source |
|---|---|---|---|
| Face length: Brick | 215 mm | Common UK size Not yet checked against the source | From your product UK standard brick (work size). |
| Face height: Brick | 65 mm | Common UK size Not yet checked against the source | From your product UK standard brick (work size). |
| Face length: Block | 440 mm | Common UK size Not yet checked against the source | From your product UK standard block face. |
| Face height: Block | 215 mm | Common UK size Not yet checked against the source | From your product UK standard block face. |
| Joint | 10 mm | Common UK size Not yet checked against the source | From your product Standard UK mortar joint. |
| Waste allowance | 5 % | Our assumption Not yet checked against the source | Our choice: change it to suit your job Breakages and cuts. |
Regulations and standards
- Approved Document A (structure): wall thickness, ties and support are design matters this count doesn't cover
Explained: Approved Document A (structure).
Our checks use the guidance for England unless a badge says otherwise. Wales, Scotland and Northern Ireland have their own rules: check the source for where you live.
FAQs
Guides
Garden wall planning checklist
What to check before building a garden wall: when to get a professional, foundations, boundaries and permissions, then ordering.
How many bricks per square metre?
The sum behind bricks per square metre for UK bricks and blocks, single vs double skin, breakages, and the mortar to go with them.