AbraCalc

Brick Calculator

Calculate how many standard bricks you need for a wall. Includes a mortar joint and waste allowance.

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How to use this tool

  1. Enter the wall length and height in feet.
  2. Add a waste factor (5% standard, 10% for complex patterns).
  3. 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.

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

Worked example

  1. Wall area = 20 ft × 6 ft = 120 ft².
  2. Base bricks = 120 × 7 = 840 bricks.
  3. Apply 5% waste: 840 × 1.05 = 882 bricks.
  4. Round up: ⌈882⌉ = 882 bricks.

You need 882 bricks for a 20 ft × 6 ft wall with a 5% waste allowance.

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.

References & sources