Brick calculator
This brick calculator turns the size of your wall into a shopping list: enter length, height, openings and the brick size and see bricks per square metre, the total with waste and the mortar needed.
Example: Wall length 10 m · Wall height 2.5 m · Openings (windows, doors) 4 m² · Brick size: DF 240 × 115 × 52 mm · Wall build-up: One skin (thickness = brick width) · Joint thickness 12 mm · Waste 5 % · Mortar loss 15 % → Bricks needed: 1,368 bricks for 21 m² of wall (including waste). Source: Wikipedia – Backstein (Formate DF, NF, 2DF; Maßordnung im Hochbau). Updated: .
How it is calculated
A wall of 10 × 2.5 m with 4 m² of openings built from 215 × 102.5 × 65 mm bricks with 10 mm joints needs about 1,300 bricks with waste. The calculator gives the number and the mortar for your wall.
How it is calculated
- Bricks per m²: 1 ÷ ((length + joint) × (height + joint)) in stretcher bond. For a standard UK brick with 10 mm joints that is about 60 per square metre.
- Two skins: a full brick thickness needs twice as many bricks.
- Mortar: wall volume minus brick volume, plus an allowance for loss.
The sizes
The standard UK brick is 215 × 102.5 × 65 mm, the US modular brick 7⅝ × 3⅝ × 2¼ inches and the German DF brick 240 × 115 × 52 mm. For any other country choose Own size and enter length, width and height in millimetres.
What matters
A thick joint raises mortar use and lowers the brick count. Allow 3 to 5 percent waste, more at corners and openings.
Related: the concrete calculator, the square metre calculator and the tile calculator.
Frequently asked questions
How many bricks do I need per square metre?
A standard UK brick (215 × 102.5 × 65 mm) with 10 mm joints needs about 60 per m² of wall face in one skin, a US modular brick about 7 per square foot.
How do I work out the number of bricks for a wall?
Wall area (length times height minus openings) times bricks per square metre. Add 3 to 5 percent for waste.
How much mortar do I need?
The wall volume minus the brick volume. For a single-skin wall of standard bricks it is roughly 18 to 26 litres per m², plus some loss.
What do the brick formats mean?
They are standard sizes: the UK brick is 215 × 102.5 × 65 mm, the US modular brick about 194 × 92 × 57 mm. The calculator also accepts your own size.
Does it work for blocks or aircrete?
Yes, if you enter the size under Own size and adjust the joint. Thin-bed mortar has joints of only 1 to 3 mm.
Sources and legal basis
- Wikipedia – Backstein (Formate DF, NF, 2DF; Maßordnung im Hochbau)
- Wikipedia – Brick (Standardgrößen: UK 215 × 102,5 × 65 mm, US modular)
As of: · Editorial policy
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