How to use this calculator
Enter the length and height of the wall and the area of any openings, then choose the brick or block size. Sizes are nominal — the actual unit plus a ⅜-inch mortar joint — which is how the Brick Industry Association tabulates units per square foot. The count is for one wythe (one brick thick); double it for a two-wythe wall.
The default waste allowance is 5%, for breakage and cuts. Raise it to 10% for walls with many corners, openings or decorative bonds. Running the calculator backwards tells you how much wall a pallet will build: enter the number of bricks and the wall height to get the length.
The formula
- l
- wall length
- h
- wall height
- A
- wall area
- A_open
- openings area
- A_net
- net wall area
- w%
- waste allowance
- N
- bricks or blocks needed
Worked example
A garden wall 20 ft long and 8 ft high, with a 20 ft² gateway opening, is to be built in modular brick, single wythe.
- Wall area = 20 × 8 = 160 ft²; minus the opening = 140 ft².
- Modular brick (nominal 8 × 2⅔ in face) lays at 6.75 per ft².
- Bricks = 140 × 6.75 × 1.05 = 992.3, so 993 bricks.
Order about 1,000 modular bricks. A double-wythe wall needs twice as many.
Units per square foot of wall
| Unit (nominal face) | Per ft² | Per m² |
|---|---|---|
| Modular, 8 × 2⅔ in | 6.75 | 72.7 |
| Engineer modular, 8 × 3⅕ in | 5.63 | 60.5 |
| Closure modular, 8 × 4 in | 4.50 | 48.4 |
| Roman, 12 × 2 in | 6.00 | 64.6 |
| Norman, 12 × 2⅔ in | 4.50 | 48.4 |
| Utility, 12 × 4 in | 3.00 | 32.3 |
| Concrete block, 16 × 8 in | 1.125 | 12.1 |
Assumptions and limits
- Running bond, single wythe, ⅜-inch (10 mm) joints. Thicker joints reduce the count slightly.
- Mortar, wall ties, lintels and footings are not included.
Frequently asked questions
How many bricks are in a square foot?
For standard US modular brick with ⅜-inch joints, 6.75 per square foot of wall face (one wythe).
How many concrete blocks do I need per square foot?
A standard 8 × 8 × 16 in block has a nominal face of 128 in², so 1.125 blocks per square foot, or 112.5 per 100 ft².
How much extra brick should I order?
About 5% for straight walls. Allow 10% or more for curved walls, many openings, or bricks you will cut for patterns.
Sources
- Brick Industry Association — Technical Notes (TN 10: Dimensioning and Estimating Brick Masonry)
- National Concrete Masonry Association — TEK notes
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