Brick Calculator
Calculate how many bricks or blocks a wall needs, including mortar joints and waste.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Estimate units for a single-skin wall using typical face coverage for the selected brick or nominal block size. Actual coverage depends on the product dimensions, mortar joint and laying pattern.
Worked example
calculated with the default values below
Wall length 20 ft · Wall height 8 ft · Brick type Modular brick (6.5 per sq ft) · Doors and windows to subtract 0 sq ft · Waste allowance 7 % · Price per brick or block 0.6 $ Net wall area 160.0 sq ft · Bricks per square foot 6.50 · Bricks needed 1,113 · Estimated material cost 667.80 $
General background references
Disclaimer
These calculators provide planning estimates only. Building codes, wiring regulations and safety requirements differ by country and change over time, and nothing here replaces a licensed professional or a permit. For structural, electrical or gas work, follow local code and have the installation inspected.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
N = ⌈A × d × (1 + w ÷ 100)⌉; A = max(0, L × H − A₀)
- N
- Bricks needed (rounded up)
- A
- Net wall area, sq ft
- d
- Bricks per sq ft by brick type
- w
- Waste allowance, %
- L
- Wall length, ft
- H
- Wall height, ft
- A₀
- Area of doors and windows subtracted, sq ft
Estimated units = ceil((wall length × height − openings) × units per sq ft × (1 + waste/100)). Typical face coverage assumptions: modular 6.5, queen 5.5, king 4.5, nominal 8 in block 1.125 and nominal 12 in block 1.125 per sq ft. Both block sizes assume a 7 5/8 × 15 5/8 in face; verify actual product dimensions and bond.
Frequently asked questions
How many CMU blocks fit one square foot?
The estimate uses typical face coverage per square foot: 6.5 modular, 5.5 queen, 4.5 king, or 1.125 for either nominal 8 in or 12 in CMU. The 12 in size is the wall thickness; its exposed face is commonly the same 8 × 16 in nominal module as the 8 in block, so the count per wall area stays the same. Actual dimensions, mortar joints and bond can change coverage.