Free calculator
Brick and block calculator
Enter the wall size, take out the doors and windows, choose your brick or block, and get how many to buy plus the mortar volume.
Result
- Wall area to build
- 12.4 m²
- Units per area
- 59.3 per m²
- Bricks or blocks (exact)
- 735
- To buy with 5% waste
- 772
- Mortar volume (wet)
- 0.218 m³ (218 L)
Single-skin wall, one unit thick. Mortar is the geometric joint volume, the least the wall takes; add a margin for waste and see the bag for dry-mix yield.
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Labour, extra items, margin and tax on top of the material list. Printed with your logo, saved as PDF. Works from the 3D room planner.
How it works
Each brick occupies its own size plus one mortar joint on the top and one on the end. Units per square metre = 1 ÷ ((length + joint) × (height + joint)). A UK standard brick (215 × 65 mm with a 10 mm joint) works out at 59.3 per square metre, a 73 mm Scottish brick at 53.5 and an imperial 228 × 73 mm brick at 50.6; a 440 × 215 mm block at 9.88 (see how many blocks per m²). A US modular brick is 6.86 per square foot and an 8 × 8 × 16 in concrete block 1.125. The UK bricks and blocks per m² table adds the mortar for each.
The net area is the wall face minus openings. Mortar volume is the wall volume minus the volume taken by the units themselves, which is exactly the bed and head joints. Real jobs use more, because mortar is wasted and joints are not perfectly uniform, so add a margin and check the dry-mix bag for its yield.
The result is for a single-skin wall one unit thick. For a double-skin or cavity wall, calculate each skin separately. A round fire pit is counted per course instead, in the fire pit brick calculator.
Frequently asked questions
- How many bricks are in a square metre?
- 59.3 standard UK/EU bricks (215 × 65 mm) laid with 10 mm joints, which is where the "60 per square metre" rule comes from. A 73 mm brick is 53.5 (215 mm long) or 50.6 (imperial, 228 mm long). Thin-joint or larger-format bricks change the figure, which is why the calculator uses the actual size and joint.
- How many blocks per m2?
- 9.88 concrete blocks (breeze blocks) of 440 × 215 mm per square metre with a 10 mm joint, about 10.4 with 5% waste. The block's thickness (100, 140 or 215 mm) does not change the count.
- How many bricks per square foot?
- 6.9 US modular bricks with 3/8 in joints, or 1.125 concrete blocks of 8 × 8 × 16 in.
- How much waste should I allow for bricks?
- Five percent is usual for straight walls. Add more for walls with many cuts, corners or damaged deliveries.
- Does it calculate mortar bags?
- It gives the mortar volume. Bag yields vary a lot between products, so take the volume, add waste, and use the yield printed on the bag you are buying.
Guides
- How many bricks per square metre (and per square foot)?
Bricks and blocks per square metre and per square foot for the common formats, how the mortar joint changes the count, and what to order for a 10 m² wall.
- How many bricks per square foot? Walls, patios and floors
Modular bricks per square foot of wall (about 7) and laid flat on a patio (4.5 to 5), bricks for 100 to 500 sq ft with 5% waste, mortar, and the UK brick per sq ft.
- How many bricks do I need for a fire pit? Fire pit brick calculator for 30 to 48 inch pits
A 36 in round fire pit takes 16 modular bricks a course, 84 for 5 courses with 5% waste, and 14 fire bricks a course to line it. 30 to 48 in, square pits.
- How many blocks for a retaining wall? (12x4, 16x6 and 18x8 in)
Retaining wall blocks for 10 to 50 ft walls at 1, 2 and 3 ft high in the three common sizes, plus the gravel base and the drainage stone behind the wall, and metric.
- How many bags of mortar per 100 bricks (and per 100 blocks)?
80 lb and 60 lb mortar bags per 100, 500 and 1,000 bricks or 8x8x16 blocks from the label yields, mortar volume per square metre of wall, and 25 kg bags for UK bricks.
- How many 73mm bricks per m2? Single and double skin, imperial bricks and mortar
53.5 bricks per m² for a 215 x 102.5 x 73 mm brick, single skin, 10 mm joints (56.2 with 5% waste, 107.1 double skin); 50.6 for 228 x 108 x 73 mm imperial.
- How many blocks per m2? 440 x 215 concrete and breeze blocks, mortar and waste
Standard 440 x 215 mm blocks with a 10 mm joint: 9.88 per m², 10.4 with 5% waste, 19.8 for two leaves, 0.9 bags of 25 kg mortar per m². Laid flat: 20.2.