Brick is estimated with the "wall-area method": take the net area of the wall (gross area minus openings) and multiply by the number of bricks that fill one square foot. The Brick Industry Association (BIA) describes this as the most widely used estimating procedure in its Technical Note 10, Dimensioning and Estimating Brick Masonry, and publishes the bricks per square foot and mortar per 100 ft² for each standard modular size. This brick calculator uses those published figures, so a standard modular brick wall uses 6.75 bricks per square foot with ⅜ inch mortar joints.
Mortar sand is ordered separately; BIA cites the rule of thumb that one cubic foot of loose, damp sand yields about one cubic foot of mortar, so you can convert the mortar result with the sand calculator. For a brick wall's footing, use the concrete slab calculator.
How to use the brick calculator
- Measure the length and height of each wall face to be bricked and add the faces together, or run one wall at a time.
- Enter the total area of windows and doors to subtract.
- Choose your brick size. Names follow BIA's nominal dimensions (width × height × length, including the mortar joint).
- Keep a waste allowance; BIA tells estimators to allow for breakage and waste without fixing a percentage, so 5% is a common starting point, more for chipping-prone or tumbled brick.
- Enter a price per brick to estimate cost.
Formula
Bricks per ft² and mortar per 100 ft² come from BIA Technical Note 10, Table 4, for ⅜ inch joints in running or stack bond, single wythe. Mortar figures are theoretical and exclude waste.
Worked example
A 20 × 8 ft garden wall face with a 15 ft² opening, modular brick, 5% waste.
- Net area: 20 × 8 − 15 = 145 ft².
- Bricks: 145 × 6.75 = 978.75 before waste.
- With 5%: 978.75 × 1.05 = 1,027.7, so 1,028 bricks.
- Mortar: 145 ÷ 100 × 5.5 = 7.98 ft³, before waste (about the same volume of damp sand).
- Masonry cement, by BIA's very rough rule of 8 bags per 1,000 modular brick: 1,028 × 8 ÷ 1,000 = 8.2, so about 9 bags.
Bricks per square foot by size (BIA TN 10)
| Brick | Nominal W × H × L (in) | Bricks per ft² | Mortar ft³ per 100 ft² |
|---|---|---|---|
| Modular | 4 × 2⅔ × 8 | 6.75 | 5.5 |
| Engineer modular | 4 × 3⅕ × 8 | 5.63 | 4.8 |
| Closure modular | 4 × 4 × 8 | 4.50 | 4.1 |
| Roman | 4 × 2 × 12 | 6.00 | 6.4 |
| Norman | 4 × 2⅔ × 12 | 4.50 | 5.1 |
| Engineer Norman | 4 × 3⅕ × 12 | 3.75 | 4.4 |
| Utility | 4 × 4 × 12 | 3.00 | 3.7 |
All with ⅜ inch joints. With ½ inch joints, BIA's mortar quantities are higher (for modular brick, 6.9 ft³ per 100 ft²). Brick names and actual sizes can vary between manufacturers, so confirm your product's specified dimensions.
Bond patterns and double walls
The table assumes running bond or stack bond in a single wythe (one brick thick), which covers most veneer and garden walls. Patterns with header courses, such as Flemish or English bond, use extra brick; BIA TN 10 gives correction factors for them. For a double-wythe garden wall, multiply the brick count by two (plus any headers) and estimate the collar joint mortar separately.
Caveats and assumptions
- Counts are for single-wythe running or stack bond. Headers, corners, soldier courses and decorative patterns add brick.
- Mortar quantities are theoretical; real-world use is higher because of droppings and joint variations.
- The masonry cement rule of thumb (8 bags per 1,000 modular brick) is described by BIA as very rough. Follow your mortar product's yield for ordering.
- Structural brick walls and veneer anchorage must follow your local building code.
Frequently asked questions
How many bricks are in a square foot?
For standard modular brick with ⅜ inch joints, 6.75 bricks per square foot (675 per 100 ft²), according to BIA Technical Note 10. Larger bricks such as Norman (4.5) or utility (3.0) need fewer.
How many bricks do I need for a 10 × 10 wall?
100 ft² × 6.75 = 675 modular bricks, or about 709 with 5% waste.
How much mortar do I need for 1,000 bricks?
BIA lists about 8.1 ft³ of mortar per 1,000 modular brick with ⅜ inch joints, before waste.
How much sand for brick mortar?
BIA cites a rule of thumb that one cubic foot of loose, damp sand yields about one cubic foot of mortar, so order roughly the mortar volume in sand plus a margin.
How much extra brick should I order?
About 5% is a common allowance for breakage and cuts. Buy enough from one production run; colors can vary between batches.
Sources
- Brick Industry Association — Technical Note 10: Dimensioning and Estimating Brick Masonry — Table 4 brick and mortar quantities; wall-area method
- Brick Industry Association — Technical Notes index — TN 10 summary
This calculator gives estimates for planning and education. Check measurements, local codes, supplier specs and your school's official policy before relying on a result. See our disclaimer and how we build and check calculators.