Brick Wall Calculator
Calculate how many bricks you need to build a wall, from a single-skin garden wall to a full one-brick (double skin) wall. Deduct doors and windows, choose your brick size, and get the brick count plus the mortar, cement and sand.
Calculate bricks for a wall
Brick calculation formula
Bricks needed
Bricks = ⌈(L × H − openings) × bricks per m² × skins × (1 + waste%)⌉Bricks per m² = 1 ÷ [(brick length + joint) × (brick height + joint)]. A UK brick with a 10 mm joint covers 0.225 × 0.075 = 0.016875 m², so one skin needs 59.26 bricks per m².
Mortar
Mortar per brick = [(length + joint) × joint + height × joint] × brick depthThat is one bed joint and one cross (perp) joint per brick. A double-skin wall also gets a 10 mm collar joint between the skins. The calculator adds 15% for droppings, then converts to dry materials with a 1.33 factor.
Bricks per square metre and square foot
| Brick | Joint | Per m² (single skin) | Per ft² | Mortar per m² |
|---|---|---|---|---|
| UK 215 × 102.5 × 65 mm | 10 mm | 59.3 (use 60) | 5.5 | 0.018 m³ |
| 9 × 4½ × 3 in (228 × 114 × 76 mm) | 10 mm | 48.9 | 4.5 | 0.017 m³ |
| Modular 190 × 90 × 90 mm | 10 mm | 50.0 | 4.6 | 0.013 m³ |
| US modular 7⅝ × 2¼ in | ⅜ in | 72.7 | 6.75 | ≈ 8.1 ft³ per 1,000 |
| US standard 8 × 2¼ in | ⅜ in | 70.5 | 6.55 | ≈ 8.4 ft³ per 1,000 |
Mortar figures are net (no waste). A double-skin wall uses twice the bricks and a little more than twice the mortar.
Mortar mix and materials
Metric results use a 1 : 5 cement : sand mortar with 1,440 kg/m³ cement density. US results use a 1 : 3 masonry cement : sand mix, where one 70 lb bag of masonry cement is about 1 ft³ and the sand volume roughly equals the mortar produced. See the Mortar Mix Calculator to change the ratio.
Worked examples
- Area = 10 m²
- Bricks = 10 × 59.26 = 592.6, +5% = 623 bricks
- Mortar ≈ 10 × 0.0176 × 1.15 = 0.20 m³ → about 65 kg cement (3 × 25 kg) and 0.22 m³ sand
- Area = 96 ft²
- Bricks = 96 × 6.75 = 648, +5% = 681 bricks
How to use the calculator
- Choose units and brick size. The list switches between metric and US bricks.
- Enter the wall length and height, and the total area of any doors or windows.
- Choose single or double skin. A half-brick wall is one brick thick lengthways; a one-brick wall is two skins side by side.
- Add waste and calculate. 5% is typical; allow 10% for cut-heavy work or reclaimed bricks.
Frequently asked questions
How many bricks are in 1 m² of wall?
About 60 standard UK bricks per m² for a single-skin (half-brick) wall with 10 mm joints, and about 120 for a double-skin wall.
How many bricks per square foot?
US modular bricks with ⅜ in joints work out at 6.75 per ft² for a single wythe; US standard bricks are about 6.55 per ft².
How much mortar for 1,000 bricks?
About 0.30 m³ of wet mortar for 1,000 UK bricks in a single skin, before waste. For US modular brick it is about 8.1 ft³ per 1,000.
How many bricks in a 9 inch wall?
A 9 in (one-brick) wall built with 9 × 4½ × 3 in bricks uses about 98 bricks per m² of wall face, or about 9.1 per ft².
Related calculators
Results are estimates for ordering. Brick sizes vary between manufacturers, so confirm the exact size with your supplier.