Brick Calculator
Calculate how many standard bricks you need for a wall. Includes a mortar joint and waste allowance.
How to use this tool
- Enter the wall length and height in feet.
- Add a waste factor (5% standard, 10% for complex patterns).
- The result shows total wall area and number of bricks to purchase.
Estimate the number of bricks needed before starting your wall or garden project.
⚠ This tool provides general estimates for education only and is not financial, tax or legal advice. Figures may not reflect your situation — verify with a qualified professional.
Formula
Wall area = length (ft) × height (ft)
Bricks = ⌈ wall area × 7 × (1 + waste% ÷ 100) ⌉
The factor 7 represents approximately 7 standard bricks per square foot, accounting for a ⅜ in mortar joint.
How it works
This calculator estimates the number of standard modular bricks (3⅝ × 2¼ × 7⅝ in nominal) for a single-wythe wall. A coverage rate of 7 bricks per square foot is used, which already incorporates a standard ⅜ inch mortar joint. The waste percentage is added on top to cover cuts, breakage, and pattern offcuts; the result is always rounded up to the nearest whole brick. The calculation applies to single-leaf walls only — double-wythe or cavity walls require doubling the brick count.
Worked example
- Wall area = 20 ft × 6 ft = 120 ft².
- Base bricks = 120 × 7 = 840 bricks.
- Apply 5% waste: 840 × 1.05 = 882 bricks.
- Round up: ⌈882⌉ = 882 bricks.
You need 882 bricks for a 20 ft × 6 ft wall with a 5% waste allowance.
Common mistakes to avoid
- Using the 7 bricks/sq ft factor for non-standard brick sizes -- modular queen, jumbo, or utility bricks all have different coverage rates.
- Forgetting to add a waste factor for cuts at corners and openings; 5-10% extra is standard, but decorative bonds like herringbone need 15%+.
- Measuring wall area including windows and doors, then ordering enough bricks to fill the whole area including those openings.
Key terms
- Standard modular brick
- A common US brick measuring 3⅝ × 2¼ × 7⅝ inches (nominal 4 × 2⅔ × 8 in), the basis for the 7-bricks-per-square-foot coverage rate.
- Mortar joint
- The layer of mortar between bricks; a standard joint is ⅜ inch thick and is factored into the 7 bricks/ft² coverage rate.
- Wythe
- A vertical layer of brickwork one brick thick. A single-wythe wall uses one brick per layer; a double-wythe wall would need twice as many bricks.
- Waste allowance
- An extra percentage of bricks ordered to cover breakage, cuts at corners or openings, and pattern requirements. Five percent is common for straight runs; 10% or more for complex patterns.
Frequently asked questions
- How many bricks per square foot?
- Standard US bricks (3.75"×2.25"×8") with a 3/8" mortar joint require approximately 7 bricks per square foot of single-wythe wall.
- How much mortar do I need for bricks?
- As a general rule, you need about 1 bag of mortar mix per 30–40 bricks when laid in standard bond pattern.