Work out how many bricks you need for a wall, plus mortar and cost. Enter the wall size, pick a brick (UK 215 × 102.5 × 65 mm by default) and get bricks per square metre and the total to order with waste.
This brick calculator tells DIYers, self-builders and trades how many bricks to order for a wall and roughly how much mortar to mix. It works in metric first and accepts any brick size, so it suits the UK standard brick, German formats and imported bricks alike. Measure the wall, take off doors and windows, and the tool adds your waste allowance and rounds up to whole bricks.
How many bricks per square metre?
A UK standard brick is 215 × 102.5 × 65 mm. With 10 mm mortar joints each brick covers 225 × 75 mm of wall, so a half-brick wall needs 59.3 bricks per square metre, usually rounded to 60. A one-brick (double skin) wall needs about 120 per square metre. Add 5 to 10% for waste.
How does the brick calculator work?
It divides the wall area by the face area of one brick plus one mortar joint, then multiplies by the number of brick leaves in the wall thickness.
Bricks = bricks per m² × leaves × (wall area − openings)
Order = bricks × (1 + waste % ÷ 100), rounded up
Mortar volume = area × leaves × (brick width − bricks per m² × brick volume), plus the collar joint in a one-brick wall
Width does not change the brick count for a single leaf, but it does change the mortar volume, because a wider brick has wider bed joints. A one-brick wall is two leaves deep with a 10 mm collar joint between them, so it needs twice the bricks and a little more than twice the mortar. Need the area of an odd-shaped wall first? Use the square footage calculator, which also works in square metres.
How many bricks per m² for UK, German and US bricks?
Here are the counts the formula gives with no waste added. Brick sizes are the actual (work) sizes in millimetres.
| Brick | Size (mm) | Joint | Half-brick wall | One-brick wall |
|---|---|---|---|---|
| UK standard | 215 × 102.5 × 65 | 10 mm | 59.3 per m² | 118.5 per m² |
| German Normalformat (NF) | 240 × 115 × 71 | 10 mm | 49.4 per m² | 98.8 per m² |
| German Dünnformat (DF) | 240 × 115 × 52 | 10 mm | 64.5 per m² | 129.0 per m² |
| US modular | 194 × 92 × 57 | 9.5 mm (3/8 in) | 73.8 per m² (6.86 per sq ft) | 147.6 per m² |
The UK figure of 60 per m² that merchants quote is 59.26 rounded up. German formats were set up so that a brick plus a 1 cm joint fits a grid of 1/8 metre units, which keeps wall lengths tidy. For a cavity wall with brick on both sides, double the half-brick figure. If the inner leaf is concrete block, count only the outer leaf here.
How much mortar do I need for 1,000 bricks?
About one tonne. The Mineral Products Association’s mortar data sheet states that 1 tonne of cement, lime and sand mortar lays approximately 1,000 bricks or 600 blocks. The calculator shows that figure, plus the net volume of the joints for solid bricks. The tonnage rule is higher than the net volume because frogs and perforations fill with mortar and some is always dropped, so order from the tonnage figure.
| Mortar class | Site mix, cement:lime:sand | Exposure listed |
|---|---|---|
| M12 | 1:¼:3 | Severe |
| M6 | 1:½:4 to 4½ | Severe |
| M4 | 1:1:5 to 6 | Moderate |
| M2 | 1:2:8 to 9 | Passive |
Ratios are by volume, as listed in MPA Mortar Data Sheet 01 (issue 10, October 2023). Your brick maker or engineer may specify a class for your exposure, so check before mixing. The “bags” figure assumes 25 kg bags of pre-mixed mortar, 40 to the tonne.
Worked example: a garden wall in Cork
Siobhan is building a garden wall 6 m long and 1.2 m high in half-brick, using standard 215 × 102.5 × 65 mm bricks. The wall is 7.2 m². At 59.26 bricks per m² that is 426.7 bricks, and with 5% waste she should order 448 bricks. By the MPA rule she needs about 0.45 tonnes of mortar, or 18 bags of 25 kg. If her merchant charges €650 per 1,000 (enter your own quote), the bricks cost about €291.
How much extra brick should I allow for waste?
Allow 5% for a plain wall and up to 10% when there is a lot of cutting, piers or corners. UK merchants commonly advise 5 to 10% extra for breakage and cuts. For flooring or wall tiles on the same project, the tile calculator uses the same waste logic.
How Do You Use the Brick Calculator?
Enter the wall size
Choose meters or feet, then enter the wall length, height and the area of any doors or windows to leave out.
Pick the brick and joint
The UK standard brick with 10 mm joints is preset. Choose a German or US size, or type any custom size.
Set waste and price
Keep 5% waste for a simple wall. Add your merchant’s price per 1,000 bricks in euros, pounds or dollars to see the cost.
Read your order
The big number is the bricks to order. Below it are bricks per m², mortar volume, mortar tonnes, bags and cost.
Frequently Asked Questions
How many bricks are in a square metre of wall?
For UK standard bricks with 10 mm joints, 59.3 bricks per square metre in a half-brick wall, normally rounded to 60. A one-brick (double skin) wall needs about 120 per square metre.
What size is a standard UK brick?
215 mm long, 102.5 mm wide and 65 mm high. With a 10 mm joint it takes up 225 × 112.5 × 75 mm, which is called the co-ordinating size.
How many bricks do I need for a 10 m² wall?
About 593 bricks for a half-brick wall using UK standard bricks with 10 mm joints. With 5% waste, order 623. A one-brick wall of the same size needs about 1,245 with 5% waste.
How much mortar do I need per square metre of brickwork?
Roughly 60 kg for a half-brick wall in UK bricks, using the MPA guide that one tonne of mortar lays about 1,000 bricks. The net volume of the joints for solid bricks is about 0.018 m³ per square metre.
Does joint thickness change the brick count?
Yes. Thicker joints mean each brick covers more wall. With 15 mm joints, UK bricks drop to about 54 per square metre, so always enter the joint you will actually use. 10 mm is the UK standard.
Should I count a cavity wall as one wall or two?
Choose “Cavity, two brick leaves” when both leaves are brick, which doubles the count. If the inner leaf is concrete block, pick half-brick so only the outer facing leaf is counted.
Sources and Further Reading
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Last reviewed: October 2026