How to Calculate Brick and Mortar Quantity
Bricks per square foot of wall, and mortar as a percentage on top
Bricks per square foot
A standard modular brick with its mortar joint occupies a fixed face area — commonly cited as around 7 bricks per square foot for standard modular brick with ⅜-inch joints, though this varies with the specific brick size and joint thickness used. Multiply the wall area (minus door and window openings) by the bricks-per-square-foot figure for your specific brick to get the total count.
Always add a waste allowance
Bricks break, get cut at corners and openings, and some are rejected for chips or color variation. A waste allowance of around 5-10% on top of the calculated count is standard practice.
Mortar is a separate, smaller-volume calculation
Mortar fills the joints between bricks, not the bricks themselves — it's typically only around 10-15% of the wall's gross volume, though this depends on joint thickness and brick size. Mortar quantity is usually estimated per 1,000 bricks (using product-specific yield data from the mortar manufacturer) rather than calculated from first principles on most job sites, since mortar mix yield varies by product and mixing ratio.
Worked Example
A wall area of 200 ft², using standard modular brick at ~7 bricks/ft², with 10% waste.
Base count: 200 × 7 = 1,400 bricks
With 10% waste: 1,400 × 1.10 = 1,540 bricks
Assumptions & Limitations
- Bricks-per-square-foot and mortar-yield figures vary by product — always confirm against the specific brick and mortar mix being used.