Show the formula and working
This brick calculator works out how many bricks you need for a garden wall, extension wall, planter or barbecue, from the wall size, the brick size and the wall thickness. It is set up for UK standard bricks and metric measurements, with a feet and inches switch, and it also shows bricks per square metre, the number of packs and the mortar that fills the joints.
Quick answer: A half brick wall of UK standard bricks with 10 mm joints needs 59.3 bricks per square metre, often rounded to 60. A one brick thick wall needs 118.5. Multiply by the wall area and add about 5% for cuts. The brick calculator gives 312 bricks for a 5 m by 1 m wall.
What Is a Brick Calculator?
A brick calculator is a tool that turns the area of a wall into the number of bricks needed to build it. Each brick, plus half a joint all round, covers a face of (brick length + joint) x (brick height + joint). One square metre divided by that face gives bricks per square metre for one leaf. Multiply by the net wall area, by the number of leaves, and by 1 plus your waste allowance, then round up.
The UK standard brick measures 215 x 102.5 x 65 mm, and with a 10 mm joint it takes up 225 x 75 mm on the face of the wall, as set out in the Wikipedia article on bricks. So 1 / (0.225 x 0.075) = 59.26 bricks per square metre.
How Do You Use the Brick Calculator?
- Choose the Wall thickness: half brick (a single skin) or one brick (two skins side by side).
- Enter the Wall length and Wall height.
- Enter the total area of Doors, windows and gaps to leave out, or 0 for a solid wall.
- Check the Brick length, Brick height, Brick width and Mortar joint. The defaults are a UK standard brick with a 10 mm joint.
- Set the Extra for cuts and breakages and the Bricks per pack (from supplier).
- Read the number of bricks, bricks per square metre and packs, then open “Show the formula and working” to see each step.
How Many Bricks Are in a Square Metre?
There are 59.3 UK standard bricks in one square metre of half brick wall with 10 mm joints, and 118.5 in a one brick thick wall. Builders often round this to 60 and 120 per square metre. Bricks of other sizes give different figures, so enter the size printed on the pack or the manufacturer’s data sheet.
The face size is what matters. Brick width only changes the wall thickness and the mortar volume, not the count per square metre of one leaf.
| Brick format | Size (mm) | Bricks per m², half brick wall, 10 mm joints |
|---|---|---|
| United Kingdom | 215 x 102.5 x 65 | 59.3 |
| Germany | 240 x 115 x 71 | 49.4 |
| Denmark | 228 x 108 x 54 | 65.7 |
| Sweden | 250 x 120 x 62 | 53.4 |
| Australia | 230 x 110 x 76 | 48.4 |
| United States modular | 194 x 92 x 57 | 73.2 |
Sizes are the national standard bricks listed by Wikipedia. Joint widths vary by country, so change the Mortar joint field if your bricklayer uses a different joint.
How Many Bricks Do I Need for a Garden Wall?
Multiply the wall length by the height, then by 59.3 for a half brick wall or 118.5 for a one brick wall, and add 5% for cuts. A 5 m long wall 1 m high in half brick needs 297 bricks before waste and 312 with 5% extra. The same wall one brick thick needs 623 bricks with waste.
Remember piers, copings and any courses below ground on the footing. Add piers as extra wall area, and count coping bricks separately, laid on edge along the top. A tall freestanding half brick wall can be unstable, so ask a builder or structural engineer about piers or a thicker wall.
How Much Mortar Do Bricks Need?
The joints of a half brick wall of UK standard bricks hold about 0.018 m³ of mortar per square metre, or 18 litres, before any waste. The calculator works this out as the wall volume minus the volume of the bricks. Real use is higher because frogs get filled and some mortar is dropped, so allow extra when you order.
Do You Need Planning Permission for a Brick Wall?
In England, a garden wall usually needs no planning permission if it is no more than 2 metres high, or 1 metre next to a road used by vehicles or its footpath. The Planning Portal guidance on fences, gates and garden walls lists the exceptions, such as listed buildings. Rules elsewhere in the UK and Europe differ, so check with your local planning authority.
Worked Example: A Garden Wall
Example: a solid garden wall is 5 m long and 1 m high in half brick, using UK standard bricks with 10 mm joints. Add 5% for cuts and breakages, and note that the supplier sells packs of 500.
- Net area: 5 m x 1 m = 5 m².
- Bricks per m²: 1 / (0.225 m x 0.075 m) = 59.26.
- Bricks: 5 m² x 59.26 x 1.05 = 311.1, rounded up to 312 bricks.
- Packs: 312 bricks fit in 1 pack of 500.
- Mortar in the joints: 0.088 m³ before waste.
If you plan to paint the finished wall, use the masonry paint calculator once the mortar has cured. More tools for the house and garden are in our home calculators.
Brick Calculator FAQs
How many bricks are in 1 m² of wall?
A half brick wall of UK standard 215 x 65 mm bricks with 10 mm joints has 59.3 bricks per square metre, usually rounded to 60. A one brick thick wall has twice as many, 118.5 per square metre.
What is the size of a standard UK brick?
A UK standard brick is 215 mm long, 102.5 mm wide and 65 mm high. With a 10 mm mortar joint it takes up 225 x 112.5 x 75 mm, known as the coordinating size, which makes setting out walls simple.
How much extra brick should I order?
Order about 5% extra for cuts and breakages on a plain wall, and more for walls with many corners, openings or decorative bonds. Buying all bricks from the same batch also helps the colour stay consistent across the wall.
What is the difference between half brick and one brick walls?
A half brick wall is a single skin 102.5 mm thick with bricks laid lengthways. A one brick wall is 215 mm thick, two skins tied together, and needs twice the bricks. One brick walls are stronger for freestanding garden walls.
How do I count bricks for a wall with a window?
Work out the window area by multiplying its width by its height, then enter it in the doors, windows and gaps field. The calculator subtracts it from the wall area before counting bricks. Keep the waste allowance, because cuts around openings add waste.
How many bricks does a bricklayer lay per day?
There is no single figure, because output depends on the bond, the height, the weather, cuts and openings. Ask your bricklayer for a quote based on the brick count from this calculator, which gives you a fair basis to compare prices.
Checked October 2026. Sources: Wikipedia: Brick (UK standard 215 x 102.5 x 65 mm and national sizes), Planning Portal: Fences, gates and garden walls.