Brick & Block Calculator
Wall area, unit module, and waste
Enter walls, openings, and masonry unit dimensions
Result
Calculation summary
Enter values to see the result
Masonry layout preview
Single masonry wall
How to use this calculator
- 1Choose one wall or combined walls, enter measured dimensions, and add doors, windows, or custom openings.
- 2Select brick or block, then choose a dimension-labeled preset or enter the exact face dimensions from the product specification.
- 3Confirm the mortar joint and waste allowance, then calculate the whole units to purchase.
Formula
Units = ceil(((gross wall area − openings) ÷ ((unit length + joint) × (unit height + joint))) × (1 + waste ÷ 100))
The wall-area method treats one unit plus one horizontal and vertical mortar joint as a planning module, then rounds the purchase quantity up.
Calculation steps
- Validate wall, opening, unit face, joint, waste, and measurement inputs.
- Convert every wall and opening to square meters and subtract openings without allowing a negative wall area.
- Convert the unit face dimensions and joint width to meters.
- Divide net wall area by the nominal module area formed by one unit and its joints.
- Apply the waste allowance and round up to a whole brick or block.
Worked example
A 5 m × 2.8 m wall has 14 m² of gross area. Using a 240 mm × 53 mm brick with a 10 mm joint gives a 250 mm × 63 mm module. With 5% waste, the estimate rounds up to 934 bricks.
Assumptions
- Walls, openings, and unit faces are rectangular; unit length and height are measured in the installed orientation.
- The estimate uses the wall-area method and one uniform bed/head joint. Bond pattern, corners, piers, returns, cuts, and special units can change the final quantity.
- Preset names are dimension labels for planning. Brick and block names and actual sizes vary by region and manufacturer.
- Openings are subtracted by area and cannot reduce the total below zero.
- Mortar volume, reinforcement, grout, wall ties, lintels, structural design, and code compliance are outside this first-version estimate.
Sources
- Technical Note 10 — Dimensioning and Estimating Brick Masonry — Brick Industry Association
- Concrete Masonry Unit Shapes, Sizes, Properties, and Specifications — Concrete Masonry & Hardscapes Association
- Handbook 133 (2026), Appendix E — General Tables of Units of Measurement — National Institute of Standards and Technology
Frequently asked questions
Which brick or block size should I use?
Use the specified face length and height from the exact product you will purchase. Names such as standard or modular can refer to different dimensions in different markets.
Does the calculator include mortar?
The joint width affects unit count, but mortar volume and bags are calculated separately. After calculating, open the linked Mortar Calculator to carry over the unit count, material dimensions, and joint.
Should I subtract doors and windows?
Yes for a planning estimate. For small openings, keeping some or all of the area can provide a practical allowance for cuts around edges and lintels.
Why are actual unit dimensions used instead of nominal dimensions?
The calculator adds the entered mortar joint to the actual face length and height to create the planning module. If your product sheet already lists a nominal module, enter actual specified dimensions and the matching joint.
Is this suitable for structural design?
No. It estimates material count only. Wall thickness, reinforcement, grout, lintels, loads, movement joints, foundations, and local code requirements need qualified design and verification.