# How many bricks do I need?

Brick calculator: how many bricks a wall needs from its length and height, less doors and windows, for US modular, UK or your own brick size with its mortar joint, plus waste and cost.

- Page: https://www.acalculator.org/construction/brick-calculator
- JSON spec: https://www.acalculator.org/construction/brick-calculator.json
- Version: 0d81ae1f3f2f

## Default answer

Example with the default inputs (Wall length 10 ft, Wall height 8 ft, Brick size US modular, 7 5/8 × 2 1/4 in, Mortar joint 0.375 in, Waste 5%): You need 576 bricks (6.857 bricks per square foot).

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| l | Wall length | The length of the wall. |
| h | Wall height | The height of the wall. |
| o | Doors and windows | The total area of doors, windows and other openings to leave out. Leave empty for none. |
| b | Brick size | The face of one brick as laid: its length and height. |
| bl | Brick length | The length of one brick. |
| bh | Brick height | The height of one brick. |
| j | Mortar joint | The thickness of the mortar joint: 3/8 in in the US, 10 mm in the UK. |
| x | Waste | Extra bricks for cuts and breakage, in percent. |
| p | Price per brick | The price of one brick. Leave empty to skip the cost. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| bricks | Bricks to buy | Net wall area × (1 + waste) ÷ the face of one brick with its joint, rounded up. |
| exactBricks | Bricks without waste | Net wall area ÷ the face of one brick with its joint, before rounding. |
| perSqFt | Bricks per square foot | 1 ft² ÷ (brick length + joint) × (brick height + joint). |
| perSqM | Bricks per square metre | 1 m² ÷ (brick length + joint) × (brick height + joint). |
| area | Net wall area | Length × height, less the openings. |
| cost | Cost | Bricks to buy × the price per brick. |

## Method

Bricks = (length × height − openings) × (1 + waste ÷ 100) ÷ ((brick length + joint) × (brick height + joint)), rounded up.

## Assumptions

- One layer of brick (a single wythe) laid in running bond; each brick fills its face plus one joint.
- US modular brick is 7 5/8 × 2 1/4 in on its face; UK standard brick 215 × 65 mm.
- Waste is 5% by default for cuts and breakage.

## Worked examples

1. l = 3.048, h = 2.4384, b = modular, j = 0.009525, x = 5% gives bricks = 576, perSqFt = 6.857143, exactBricks = 548.571429. Source: Wikipedia, Brick (US modular brick 7 5/8 × 3 5/8 × 2 1/4 in; UK brick 215 × 102.5 × 65 mm with a nominal 10 mm joint), https://en.wikipedia.org/wiki/Brick (retrieved 2026-10-03).
2. l = 5, h = 2, b = uk, j = 0.01, x = 0%, p = $0.60 gives bricks = 593, perSqM = 59.259259, cost = $355.80. Source: Wikipedia, Brick (US modular brick 7 5/8 × 3 5/8 × 2 1/4 in; UK brick 215 × 102.5 × 65 mm with a nominal 10 mm joint), https://en.wikipedia.org/wiki/Brick (retrieved 2026-10-03).
3. l = 6.096, h = 2.4384, o = 1.950964, b = custom, bl = 0.2032, bh = 0.05715, j = 0.0127, x = 10% gives area = 12.913523, bricks = 942.

## FAQ

### How many bricks are in a square foot?

About 6.86 US modular bricks. A modular brick is 7 5/8 × 2 1/4 in on its face; with a 3/8 in joint each one takes 8 × 2 5/8 = 21 in², and 144 ÷ 21 = 6.857.

### How many bricks are in a square metre?

About 59.3 UK bricks. A 215 × 65 mm brick with a 10 mm joint takes 225 × 75 mm = 0.016875 m², and 1 ÷ 0.016875 = 59.26.

### How do I work out how many bricks I need?

Multiply the wall length by the height, take away doors and windows, and divide by the face of one brick plus one joint in each direction. Add 5 to 10% for cuts and breakage and round up.

### How many bricks do I need for a 10 × 8 ft wall?

With modular brick and 3/8 in joints, 80 ft² × 6.857 = 548.57 bricks, or 576 with 5% waste (548.57 × 1.05, rounded up once).

### Does the mortar joint change the count?

Yes. A thicker joint makes each brick cover more wall, so you need fewer bricks. Use the joint your mason lays: 3/8 in is usual in the US and 10 mm in the UK.

### Is this for a single or double wall?

A single layer (one wythe) of brick. For a double wall, double the count.

## Sources

- Wikipedia, Brick: US modular brick 7 5/8 × 3 5/8 × 2 1/4 in with a 3/8 in joint; UK brick 215 × 102.5 × 65 mm with a nominal 10 mm joint, retrieved 2026-10-03. https://en.wikipedia.org/wiki/Brick
- NIST Special Publication 811 (2008), Appendix B: 1 in = 0.0254 m and 1 ft = 0.3048 m exactly, retrieved 2026-10-03. https://www.nist.gov/pml/special-publication-811