A standard United Kingdom brick measures 215 by 102.5 by 65 millimetres, and it is laid with a ten millimetre bed joint and a ten millimetre perpend. That means each brick occupies 225 by 75 millimetres of wall face, or 0.016875 square metres. Dividing one square metre by that gives 59.26 bricks, which the trade rounds to the familiar sixty per square metre — the rounding is itself a small waste allowance.
The joint is not a detail you can ignore. Bricklayers work to a gauge of four courses to 300 millimetres, which is exactly 65 plus 10 millimetres per course, and that gauge is what keeps openings, sills and wall plates at consistent heights. If you use a metric or imperial brick of a different size, change the dimensions here and the count changes with them.
A wall 8 metres long and 1.8 metres high has a face area of 14.4 square metres, so a single-skin wall needs about 854 bricks and a double-skin wall twice that. Add ten per cent for breakages, cuts at the returns and the closers at each end of a course. Bricks are then ordered in whole packs, typically four hundred to five hundred to a pack, and part packs are rarely available. That wall therefore becomes 2 packs, with the balance kept for repairs.
The formula
area- Face area of the wall in m²
length, height- Brick face dimensions in mm, normally 215 × 65
joint- Mortar joint thickness in mm, normally 10
skins- One for a half-brick wall, two for a one-brick or cavity wall
How it works, step by step
- Enter the length and height of the wall face.
- Choose whether the wall is single or double skin.
- Confirm the brick dimensions and joint thickness, or enter your own.
- The gauge shows bare bricks; packs to order appears in the breakdown.
Worked examples
A 8 × 1.8 m garden wall, single skin
14.4 m² at 59.26 bricks per m² is 854 bricks bare, or 939 with a 10% allowance. That is 2 packs of 500, and about 0.29 m³ of mortar to bed them.
A thicker joint changes the count
Laying the same wall with a 12 mm joint gives 57.21 bricks per m² instead of 59.26, so the wall takes 30 fewer bricks and correspondingly more mortar. The gauge no longer works out at four courses to 300 mm, which matters if you are matching an existing wall.
How to read your score
Frequently asked questions
Why do merchants say 60 bricks per square metre?
Because 59.26 rounds up to 60, and the extra fraction quietly covers the odd broken brick. It is a sound working figure for a 215 by 65 millimetre brick on a 10 millimetre joint, but it is wrong for imported metric bricks, which is why the dimensions are editable here.
Does a cavity wall need twice as many?
Yes for the brick count, since both leaves are built, although the inner leaf of a modern cavity wall is usually blockwork rather than brick. Set the construction to one skin and use the block calculator for the inner leaf if that is your build-up.
How many bricks will I break?
Cutting closers, bats and any angled return produces waste, and deliveries always contain a few chipped faces you will not want on show. Ten per cent is right for a straightforward wall; allow fifteen for lots of piers, returns or a curved plan.
How high can I build a single-skin wall?
A half-brick garden wall is generally limited to about 450 millimetres free-standing without piers, and to roughly 1.2 metres with piers at regular intervals, depending on exposure. Above that the wall wants to be one brick thick. Check the Building Regulations for your situation.
Do I need to allow for the foundation?
The brick count covers only what is above ground unless you enter the below-ground height too. Two or three courses of engineering brick below the damp proof course are common, so add that height to the wall before calculating.
Brick quantity reference
| Wall | Face area | Bricks bare | With 10% waste | Packs of 500 | Mortar |
|---|---|---|---|---|---|
| 2 × 0.6 m | 1.2 m² | 72 | 79 | 1 | 0.02 m³ |
| 4 × 1 m | 4.0 m² | 238 | 261 | 1 | 0.08 m³ |
| 6 × 1.2 m | 7.2 m² | 427 | 470 | 1 | 0.14 m³ |
| 8 × 1.8 m | 14.4 m² | 854 | 939 | 2 | 0.29 m³ |
| 10 × 2 m | 20.0 m² | 1186 | 1304 | 3 | 0.40 m³ |
| 12 × 2.4 m | 28.8 m² | 1707 | 1878 | 4 | 0.58 m³ |
| 20 × 2.4 m | 48.0 m² | 2845 | 3129 | 7 | 0.96 m³ |
| 30 × 2.7 m | 81.0 m² | 4800 | 5280 | 11 | 1.62 m³ |
Computed at 59.26 bricks per m². Double these figures for a one-brick or cavity wall.