Whether you are building a garden wall, adding brick veneer or laying a brick patio, the brick count comes from the same place: the area you are covering and the size of one brick including its mortar joint. Here is the formula with worked examples.
The quick formula
Number of bricks = area in square feet × bricks per square foot
Bricks per square foot depends on the brick size. For a standard US modular brick laid as a wall, the answer works out to about 7 bricks per square foot. For a brick laid flat as a paver (4 x 8 inch face), it is 4.5 bricks per square foot. The next section shows where those numbers come from so you can redo the math for any brick size.
Working out bricks per square foot for your brick
A square foot is 144 square inches. Each brick in a wall covers its face area plus the mortar joint around it. Measure the brick’s face (length and height), add the joint thickness to each, multiply, and divide into 144:
Bricks per sq ft = 144 ÷ ((brick length + joint) × (brick height + joint)), with all sizes in inches.
Worked out for a modular brick (face 7-5/8 x 2-1/4 inches) with a typical 3/8 inch mortar joint: (7-5/8 + 3/8) × (2-1/4 + 3/8) = 8 × 2-5/8 = 21 square inches. 144 ÷ 21 = 6.9, which is why 7 per square foot is the standard rule of thumb. A king size brick is larger, so the count drops; a thin brick veneer piece is smaller and the count rises. When you are unsure of the exact size, measure one brick and use the formula.
Worked examples
Garden wall, 8 feet long and 4 feet high
Area = 8 × 4 = 32 square feet. At 7 bricks per square foot: 32 × 7 = 224 bricks. Add 5 to 10 percent for cuts and breakage: buy about 235 to 245.
Brick veneer on a 20 foot wall, 8 feet high, with a door and a window
Gross area = 20 × 8 = 160 square feet. Subtract the openings: a 3 x 7 foot door is 21 square feet and a 3 x 4 foot window is 12, so 160 – 21 – 12 = 127 square feet of brick. 127 × 7 = 889 bricks. With 10 percent waste: about 975. Always subtract openings – on a wall like this they save you over 200 bricks.
Brick patio, 12 x 12 feet, bricks laid flat
Area = 144 square feet. Flat-laid 4 x 8 inch pavers cover 32 square inches each, so 144 ÷ 32 = 4.5 per square foot: 144 × 4.5 = 648 bricks. A herringbone or diagonal pattern needs more cutting, so allow 10 to 15 percent extra there instead of 5 to 10.
Do not forget waste and extras
- Waste: add 5 to 10 percent for straight walls and patios, 10 to 15 percent for patterns, curves or lots of cuts.
- Mortar: walls need mortar as well as bricks, and the amount swings a lot with joint thickness and brick size. Work it out separately once you know your joint plan.
- Base and footing: a wall needs a footing and a patio needs a compacted base. Those are separate material calculations.
- Sold by the cube or strap: bricks are often sold in wrapped cubes of a few hundred. Round your order up to whole packs and keep spares for future repairs.
Related calculators and guides
- How many concrete blocks do I need – the same math for block walls
- Square footage calculator – measure the wall or patio area first
- Concrete calculator – for the wall footing
- Paver base calculator – gravel and sand for a brick patio
Estimates only. This is general guidance, not professional advice. Confirm details with your supplier, installer or local building department.