How to use the brick calculator
Enter the wall's length and height in feet and choose the unit: one of four common brick sizes or a standard 8 × 8 × 16 in concrete block. Doors and windows are subtracted at 21 and 15 sq ft. The result is for a single wythe (one brick thick) with standard 3/8 in mortar joints. For a double-wythe wall, double the count.
The formula
- Units = wall area × units per sq ft × (1 + 5%), rounded up. The Brick Industry Association (BIA) suggests adding at least 5% for brick.
- Mortar (brick) = net bricks ÷ 1,000 × mortar per 1,000 brick × (1 + 20%). BIA suggests adding 15 to 25% for mortar.
- Bags: QUIKRETE says one 80 lb bag of Mason Mix lays up to 37 standard bricks or 13 blocks. For other brick sizes we convert by mortar volume.
Units and mortar by type
Per 100 sq ft of wall, single wythe, with the allowances above:
| Unit | Per sq ft | Mortar per 1,000 (cu ft) | Units for 100 sq ft | 80 lb bags |
|---|---|---|---|---|
| Modular brick (7 5/8 × 2 1/4 in) | 6.75 | 8.1 | 709 | 22 |
| Queen brick | 5.5 | 12.2 | 578 | 27 |
| King brick | 4.55 | 14.2 | 478 | 26 |
| Utility brick | 3 | 12.3 | 315 | 15 |
| Concrete block (8 × 8 × 16 in) | 1.125 | – | 119 | 11 |
Worked examples
A garden wall in brick
24 ft long, 3 ft high, one wythe of modular brick: 72 sq ft × 6.75 = 486 bricks, plus 5% = 511 bricks. Mortar: 4.72 cu ft with the allowance, about 16 bags of 80 lb mix.
A block wall
30 ft long and 4 ft high (six courses of 8 in block): 120 sq ft × 1.125 = 135 blocks, plus 5% = 142 blocks, and about 13 bags of mortar mix. Cap blocks, if used, are counted by length: 30 ft ÷ 16 in = 23 caps.
Masonry walls are heavy. Footings, reinforcement, and drainage behind any retaining wall are set by local code and soil conditions; walls over about 4 ft, or that hold back soil, usually need engineering and a permit.
Questions people ask
How many bricks are in a square foot?
About 6.75 modular bricks with 3/8 in joints. Queen bricks are about 5.5 per sq ft and king bricks about 4.55.
How many concrete blocks for a 100 sq ft wall?
112.5 standard 8 × 8 × 16 in blocks, so 119 with 5% extra.
Mortar mix or masonry cement?
Bagged mortar mix (like Type S or Type N) has sand already in it; you only add water. Masonry cement must be mixed with sand on site. For most DIY walls, premixed mortar is easier. Type S is common for structural and below-grade work, Type N for above-grade veneer and general use.