How to use the brick calculator
- Enter the wall size. Type the length and height of each wall. Use Add another wall for an L-shaped garden wall or all four walls of a building, or set Qty when several walls are the same.
- Subtract doors and windows. Tap a preset (a standard door is 3 × 7 ft or 0.9 × 2.1 m) or add a custom opening. The calculator removes their area so you don't over-order.
- Pick your brick. Choose a standard size — US modular, UK, South African NFP, Australian and more — or select Custom size and type the measurements printed on the pallet.
- Choose the wall build. A single-skin (half-brick) wall is one brick thick; a double-skin or cavity wall uses two leaves and therefore about twice as many bricks.
- Check waste and prices. 5–10% extra covers cuts and breakages. Add prices if you want a cost estimate. Then copy a link, email the results to yourself or print them for your supplier.
How many bricks do I need? The formula
Every brick takes up its own face area plus one mortar joint on its top and one on its end. Divide the wall area by that "brick + joint" area and you get the number of bricks:
bricks needed = net wall area × bricks per unit area × number of leaves
bricks to buy = bricks needed × (1 + waste %)
The width (depth) of the brick doesn't change the count for a single-skin wall — it only affects how much mortar you need and how thick the wall is.
Worked example in square feet
A garden wall is 20 ft long and 8 ft high with one 3 × 7 ft door: 160 ft² − 21 ft² = 139 ft² of brickwork. A US modular brick (7⅝ × 2¼ in face) with a ⅜ in joint occupies 8 × 2⅝ = 21 in², so there are 144 ÷ 21 = 6.86 bricks per square foot. 139 × 6.86 = 954 bricks, and with 10% waste you should order 1,049 bricks.
Worked example in square meters
A 5 m × 2.4 m wall with a 0.9 × 2.1 m door has 12 − 1.89 = 10.11 m² of brickwork. UK bricks (215 × 65 mm face) with 10 mm joints work out at 1 ÷ (0.225 × 0.075) = 59.3 bricks per m², so the wall needs 600 bricks, or 660 with 10% waste. With South African NFP bricks (222 × 73 mm) the same wall needs 526 bricks, or 578 with waste.
Brick calculator in square feet and square meters
If you already know your wall area, the quickest estimate is to multiply it by the bricks-per-area figure for your brick. These figures assume a single-skin wall with standard joints; the calculator above works them out for any size and joint.
| Brick | Size (L × W × H) | Joint | Per ft² | Per m² |
|---|---|---|---|---|
| US modular | 7⅝ × 3⅝ × 2¼ in | ⅜ in | 6.86 | 73.8 |
| US standard | 8 × 3⅝ × 2¼ in | ⅜ in | 6.55 | 70.5 |
| US queen | 7⅝ × 2¾ × 2¾ in | ⅜ in | 5.76 | 62.0 |
| US king | 9⅝ × 2¾ × 2⅝ in | ⅜ in | 4.80 | 51.7 |
| US utility | 11⅝ × 3⅝ × 3⅝ in | ⅜ in | 3.00 | 32.3 |
| UK standard | 215 × 102.5 × 65 mm | 10 mm | 5.51 | 59.3 |
| South Africa NFP / FBS | 222 × 106 × 73 mm | 10 mm | 4.82 | 51.9 |
| South Africa maxi | 290 × 140 × 90 mm | 10 mm | 3.10 | 33.3 |
| Australian standard | 230 × 110 × 76 mm | 10 mm | 4.50 | 48.4 |
| India modular | 190 × 90 × 90 mm | 10 mm | 4.65 | 50.0 |
See the full brick sizes chart for more formats and how nominal and actual sizes differ.
Brick calculator for walls: single, double and cavity
- Single skin (half-brick wall, 4 in / 100–110 mm). One brick thick, bricks laid lengthways in stretcher bond. Typical for brick veneer over a frame, garden walls under about 3 ft and internal partitions.
- Double skin (one-brick wall, 8–9 in / 215–230 mm). Two leaves bonded together, often in English or Flemish bond, with a mortar-filled collar joint between them. Uses twice the bricks and a little more than twice the mortar. Common for load-bearing and free-standing walls; in South Africa it's the usual 220 mm external wall.
- Cavity wall. Two leaves separated by an air gap or insulation and tied with metal wall ties — the calculator adds about 2.5 ties per m² (one per 2.5 ft²), the common 900 × 450 mm spacing. Window and door edges usually need extra ties.
Brick and mortar calculator: how the mortar estimate works
The calculator works out the volume of every mortar joint around every brick (the brick's cell minus the brick itself), adds the collar joint for double walls, then adds your mortar waste allowance. That gives the wet mortar volume. Dry cement and sand bulk down when water is added, so the dry mix is about 1.33 × the wet volume. The dry volume is then split by your mix ratio to give the cement bags and sand.
As a check: 1,000 US modular bricks with ⅜ in joints need about 8 ft³ of mortar before waste — the long-standing rule of thumb used by masons. For the 139 ft² example above, that's about 3 bags of 70 lb masonry cement and 0.44 tons of sand at a 1 : 3 mix. For more detail, use the dedicated brick mortar calculator.
How many extra bricks should I order?
Order 5% extra for simple straight walls with few cuts, and 10% for walls with lots of openings, corners, piers or decorative bonds. Bricks from different production runs can vary in color, so buying enough in one order is cheaper than trying to match later. Keep a few spare bricks for future repairs.
Tip: Bricks are sold by the pallet or in packs (commonly around 500 per pallet, but this varies by maker and size). Ask your supplier how many are on a pallet and round your order up to whole packs.
Frequently asked questions
How many bricks are in a square foot?
About 6.86 US modular bricks (7⅝ × 2¼ in face) per square foot with a ⅜ in mortar joint, or about 6.55 standard 8 in bricks. Larger formats need fewer: a king brick is about 4.8 per square foot and a utility brick about 3.
How many bricks are in a square meter?
About 60 UK bricks (59.3) per square meter of single-skin wall with 10 mm joints, about 52 South African NFP bricks, 48 Australian bricks and 74 US modular bricks. Double that for a double-skin or cavity wall.
How do I calculate bricks for a wall?
Multiply the wall length by its height, subtract the area of doors and windows, and multiply the result by the bricks per square foot or square meter for your brick and joint size. Double it for a two-leaf wall and add 5–10% for waste.
How many bricks do I need for a 10 × 10 ft wall?
A 100 ft² single-skin wall needs about 686 US modular bricks, or roughly 755 with 10% waste. With standard 8 in bricks it is about 655, or 721 with waste.
How much mortar do I need for 1,000 bricks?
About 8 cubic feet of wet mortar for 1,000 US modular bricks with ⅜ in joints, or about 0.3 m³ for 1,000 UK bricks with 10 mm joints — before waste. Allow 10–25% extra for droppings and mortar left on the board.
Does the calculator include the mortar joint?
Yes. Each brick is counted with one mortar joint on its top and one on its end. Ignoring the joint overestimates the number of bricks by roughly 15–20%.
How many bricks are on a pallet?
It depends on the manufacturer and the brick size, so ask your supplier. Enter the number under "Mortar mix & cement bag size" → "Bricks per pallet" and the calculator shows how many pallets to order.
Are these quantities exact?
They are estimates for planning and budgeting. Real walls have corners, piers, cuts and soldier courses, so check the final order with your supplier or bricklayer before you buy.