Brick Calculator
Work out how many bricks you need for a wall, single or double skin, plus the mortar, cement bags and sand to lay them.
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- Bricks to buy
- 374 bricks
- Wall area
- 6 m²
- Bricks per m² (one skin)
- 59.3
- Mortar (about)
- 356 kg
- Cement, 25 kg bags
- 3 bags
- Building sand
- 284 kg
What it does
Find how many bricks you need for a wall from its length and height, taking off doors and windows. Choose single or double skin, set the brick size and mortar joint, and add extra for cuts. It also estimates the mortar and the cement and sand to mix it.
How to use it
- Wall length
The total length of the wall. For several walls, add their lengths together if they're the same height.
- Wall height
From the top of the foundation to the top of the wall.
- Doors and windows area
The total area of any openings: width × height of each, added up. A typical door is about 1.9 m² (20 ft²).
- Wall type
Single skin is half a brick thick (102.5 mm); double skin is one brick thick (215 mm). Garden and boundary walls over about 0.5 m high are often double skin for strength. Cavity walls are two skins with a gap: use double, or work out each skin separately if one is block.
- Brick length
The face you see along the wall. UK standard bricks are 215 × 102.5 × 65 mm; US modular bricks are 7⅝ × 3⅝ × 2¼ in.
- Brick height
The height of one brick, without mortar.
- Mortar joint
10 mm is standard in the UK, ⅜ in in the US.
- Extra for cuts and breakages
5% is usual; allow 10% for lots of corners, piers or cuts.
- Mortar mix (cement : sand)
1 part cement to this many parts building sand. 1 : 4 or 1 : 5 suits most garden and house walls; follow any spec from your engineer or the brick maker.
Common uses
- Building a garden wall, raised bed or barbecue.
- Pricing up an extension or garage wall.
- Working out the concrete for the footing. Try the Concrete Calculator
- Setting out a square corner before you start. Try the 3-4-5 Rule Calculator
- Working out the paint for a rendered or painted wall. Try the Paint Calculator
The formula
Wall area = length × height − openingsBricks per m² = 1 ÷ ((brick length + joint) × (brick height + joint))Bricks = area × bricks per m² × skins, plus extra, rounded upMortar ≈ 1 kg per brick, split by the mix: cement = mortar ÷ (1 + sand parts)Where:
- skins
- 1 for a single-skin (half brick) wall, 2 for double skin
With UK standard bricks and 10 mm joints that's 59.3 bricks per m² for each skin, usually rounded up to 60. The mortar figure is a rule of thumb that allows for filled frogs and some waste: mix a little at a time and buy a few spare bags.
Worked example
A single-skin wall 5 m long and 1.2 m high, with 215 mm × 65 mm bricks and 10 mm joints:
- Wall area: 5 m × 1.2 m = 6 m²
- Each brick and its joints cover 0.0169 m², so 59.3 bricks per m²
- 6 m² × 59.3 = 355.6 bricks, plus 5% extra: 374 bricks
- Mortar: about 356 kg, which in a 1 : 4 mix is 71 kg of cement (3 bags of 25 kg) and 284 kg of sand
Questions people ask
How many bricks are in a square metre?
About 60 standard UK bricks (215 × 65 mm face, 10 mm joints) for a single-skin wall, and about 120 for a double-skin wall one brick thick.
How much sand and cement do I need for 1,000 bricks?
Roughly a tonne of mortar. In a 1 : 4 mix that's about 200 kg of cement (8 bags of 25 kg) and 800 kg of building sand, which is about one bulk bag.
Do I need planning permission or building regulations for a wall?
In England, a garden wall up to 1 m high next to a road, or 2 m elsewhere, usually doesn't need planning permission. Taller or structural walls may need permission and proper foundations. Check with your local council if unsure.
Last checked 5 November 2026 · Last rev. 31 October 2026 · 4f24