The quick answer: there are 60 standard UK bricks in a square metre of single-skin (half-brick) wall, laid with the usual 10 mm mortar joints. In Australia, where the standard brick is larger, it is about 48.5 bricks per m². For a double-skin (one-brick thick) wall, double those figures.
This guide shows where those numbers come from, how to work out the bricks and mortar for your own wall, and how much sand and cement to order. To skip the maths, use the brick and block calculator, which switches between UK, Australian and US brick sizes.
Bricks per square metre at a glance
| Unit | Size (mm) | With 10 mm joints | Per m², single skin | Per m², double skin |
|---|---|---|---|---|
| UK standard brick | 215 × 102.5 × 65 | 225 × 75 | 60 (59.3 exactly) | 120 |
| Australian standard brick | 230 × 110 × 76 | 240 × 86 | 48.5 | 97 |
| UK concrete block | 440 × 100 × 215 | 450 × 225 | 10 (9.9 exactly) | – |
| Australian concrete block | 390 × 190 × 190 | 400 × 200 | 12.5 | – |
Bricklayers round the UK figure up to 60 because it makes the sums easy and gives a small built-in allowance. You should still add waste on top, as explained below.
Where the 60 comes from
A brick on its own does not cover much wall. What matters is the brick plus half a mortar joint on each side, sometimes called the coordinating size.
- Add the joint to the face of the brick. A UK brick face is 215 × 65 mm. Add 10 mm to each: 225 × 75 mm.
- Work out the area of one brick with its joint. 0.225 m × 0.075 m = 0.016875 m².
- Divide one square metre by that area. 1 ÷ 0.016875 = 59.3 bricks, rounded to 60.
The same method gives the Australian figure: a 230 × 76 mm face plus 10 mm joints is 240 × 86 mm, or 0.02064 m², and 1 ÷ 0.02064 = 48.4, usually quoted as 48.5.
If you are using a different brick, such as a reclaimed imperial brick or a thin brick slip, measure the face and use your own numbers in the same three steps.
Worked example: a garden wall
Say you are building a single-skin garden wall 6 metres long and 1.2 metres high, with no gaps or openings.
- Wall area: 6 × 1.2 = 7.2 m²
- Bricks (UK): 7.2 × 60 = 432, plus 5% waste = 453.6, so order 454 bricks
- Bricks (Australia): 7.2 × 48.5 = 349.2, plus 5% waste = 366.7, so order 367 bricks
- Double-skin version (UK): 7.2 × 120 × 1.05 = 908 bricks
If the wall has a gate opening, work out its area and take it away before you multiply. A 1 m wide gap in that wall would take 1.2 m² off, saving about 76 UK bricks.
How much waste to allow
Bricks chip in transit, some will be the wrong colour for a face you can see, and you will cut plenty at ends and openings. As a guide:
- 5% for a straight, simple wall with few cuts
- 10% for walls with piers, corners, openings or decorative bonds
- Extra spares if the bricks are a batch that may be hard to match later. Colours vary between production runs, so it is worth buying a few more than you need and keeping them for repairs.
How much mortar do you need?
Mortar is where most DIY estimates go wrong, because it is easy to underestimate. For a single-skin wall of UK bricks, the joints alone take about 0.017 m³ of mortar per square metre. In practice, with frogs filled and some dropped on the ground, allow about 0.02–0.03 m³ per m², or roughly 0.4–0.5 m³ per 1,000 bricks.
Pre-mixed mortar bags
For a small wall, 25 kg bags of ready-to-use mortar are the simplest option: you just add water. One bag lays roughly 30–35 bricks, depending on the joint size and how much you waste. For the 454-brick wall above, that is about 13 bags. For bigger jobs, mixing your own is far cheaper.
Mixing your own: sand and cement
A standard mix for general UK brickwork is 1 part cement to 4 or 5 parts building (soft) sand, with a plasticiser to make it workable. For work below the damp-proof course, retaining walls or very exposed spots, a stronger 1:3 mix is often specified.
As a rule of thumb, 1,000 bricks need about 0.8 tonnes of building sand and 6–7 bags (25 kg) of cement. For our 454-brick wall, that is about 0.4 tonnes of sand (a small bulk bag is usually the easiest way to buy it) and 3 bags of cement.
In Australia, a common general-purpose mortar is 1 part cement, 1 part lime and 6 parts sand (M3 class). Check what your engineer or the brick manufacturer recommends, especially for load-bearing or retaining walls.
Things to check before you order
- Wall height and foundations. Even a garden wall needs a proper concrete footing. Walls over about 1 m high, retaining walls and walls near a boundary may need extra design work or approval, depending on where you live.
- Wall thickness. Tall or long garden walls are often built double-skin or with piers every few metres for stability. That doubles the bricks for those sections.
- Copings and caps. Count the top course separately if you are using special coping bricks.
- Delivery. Bricks usually come in packs of around 400–500. It can be cheaper to buy whole packs and keep the spares than to buy loose.
Frequently asked questions
How many bricks in a square metre of double-skin wall?
About 120 UK bricks, or 97 Australian bricks. A double-skin wall is simply two single skins side by side, tied together with the bond or with wall ties.
How many blocks in a square metre?
About 10 standard UK concrete blocks (440 × 215 mm face) or 12.5 standard Australian blocks (390 × 190 mm face), both with 10 mm joints.
How many bricks per square foot in the US?
About 6.86 US modular bricks (7⅝ × 2¼ in face) per square foot of single-wythe wall with 3/8-inch joints. Switch the brick calculator to USA to use US sizes.
Does the joint size really make a difference?
Yes. With 12 mm joints instead of 10 mm, a UK brick with its joint covers a little more wall, so you need about 57 bricks per m² instead of 59–60, and noticeably more mortar. Stick to 10 mm unless you are matching existing brickwork.
Work out your own wall: the free brick and block calculator gives you bricks, mortar bags and cost in UK, Australian or US sizes. Pouring a footing first? The concrete calculator covers that too.
Figures are estimates for planning. Brick sizes, bag yields and local building rules vary, so check them with your supplier before you buy.