How this brick calculator works
Bricks are bought by quantity, so the job is to work out how many bricks cover your wall. The principle is simple: bricks needed = wall area ÷ the face area of one brick, rounded up. First find the wall area by multiplying its length by its height (or enter the area directly). Then find the effective face area of a single brick by adding the mortar joint to the brick length and height and multiplying. Dividing one by the other gives the bare number of bricks, before any allowance for cuts.
Two refinements make the estimate more realistic. First, the mortar joint: each brick sits in a bond where it occupies its own size plus the joint on its top and one side, so including the joint makes each brick effectively cover a little more and you need marginally fewer. Second, the waste allowance: bricks at corners and openings must be cut, offcuts are often unusable, and the odd brick breaks — so you add a percentage (typically 10%) and round up. As a cross-check, a standard modular brick works out to roughly 7 bricks per square foot of single-wythe wall.
Standard brick sizes (face, nominal)
| Brick type | Actual face (L × H) | With 3/8 in joint | ~Per sq ft |
|---|---|---|---|
| Modular | 7.625 × 2.25 in | 8 × 2.625 in | ≈ 6.9 |
| Queen | 7.625 × 2.75 in | 8 × 3.125 in | ≈ 5.8 |
| Engineer modular | 7.625 × 2.75 in | 8 × 3.125 in | ≈ 5.8 |
| Utility | 11.625 × 3.625 in | 12 × 4 in | ≈ 3.0 |
Reference note: results are a planning estimate for a single-wythe wall in standard running bond. Wall thickness, bond pattern, corners, curves and openings all change the real count, and brick sizes vary by region and manufacturer. Measure your actual bricks, add a sensible waste allowance, and confirm coverage with your supplier before buying.
Frequently asked questions
- How many bricks do I need?
- Divide the wall area by the face area of a single brick including its mortar joint, then add a waste allowance and round up. For a standard modular brick the rule of thumb is about seven bricks per square foot of single-wythe wall. Enter your wall and brick dimensions above and the calculator returns the count both before and after waste.
- How many bricks per square foot?
- For a standard modular brick with a face of about 7.625 in × 2.25 in plus a 3/8 in mortar joint, the effective face area is roughly 0.146 sq ft, so you need about 6.9 — commonly rounded to 7 — bricks per square foot of single-wythe wall. Larger bricks need fewer per square foot and smaller ones need more.
- Does the mortar joint matter?
- Yes. Each brick occupies its own size plus the mortar joint on its top and one side, so the effective face area is (brick length + joint) × (brick height + joint). A typical joint is 3/8 in. Including it means each brick covers slightly more wall and you need marginally fewer bricks than the bare brick size alone would suggest.
- How much waste should I add?
- About 10 percent is standard to cover cuts at corners and openings, breakages on site and a few spares for future repairs. Add more for complex walls with many corners, curves or openings. The calculator adds whatever percentage you enter on top of the bare brick count and rounds up.
- What is a standard brick size?
- A US modular brick is nominally 8 in long by 2.25 in high with an actual face of about 7.625 × 2.25 in, designed to lay on a 3/8 in mortar joint to make the nominal 8 in module. Sizes vary by region and brick type, so measure your actual bricks or check the manufacturer's specification before buying.
- Should I subtract windows and doors?
- For a rough estimate many people do not, because the waste allowance covers the difference and leaves spares. For a tighter count, measure each opening and subtract its area from the wall area before dividing. This calculator includes an optional openings field so you can subtract that area when you want a closer figure.