Concrete, Brick & Masonry calculator
Block Calculator
Estimate concrete or masonry block count from wall area, block face size, joint thickness and waste.
Estimate concrete or masonry block count from wall area, block face size, joint thickness and waste. Start with measurements from the actual job and use manufacturer or supplier figures wherever the form asks for coverage, yield, density, spacing or pack size. Watch unit size and joint thickness in particular. Concrete blocks are much larger than bricks, so small changes in the face module or joint thickness materially change units per wall area. Use the exact block size.
What you need to enter
The Block Calculator uses the following project information to calculate the result.
- Wall area
- Brick / block length
- Brick / block height
- Joint thickness
- Waste (%)
Calculator result
Units required
How the Block Calculator works
The Block Calculator estimates units required from this relationship: wall area ÷ effective unit face area × allowance. Because the page is designed for concrete or masonry block quantity for a wall, the calculation depends especially on unit size and joint thickness. Metric and imperial entries are normalised before the arithmetic so equivalent measurements produce equivalent results.
Block Calculator worked example
Block Calculator example: a 24 m² wall using 440 × 215 mm blocks with 10 mm joints is calculated from the effective installed face module. The whole-unit result is then rounded up and a small breakage/cutting allowance added. The important sense-check is unit size and joint thickness, because that can move the real requirement away from the neat theoretical result.
Important calculation assumptions
For concrete or masonry block quantity for a wall, concrete blocks are much larger than bricks, so small changes in the face module or joint thickness materially change units per wall area. Use the exact block size.
Frequently asked questions
Which measurements should I confirm for the Block Calculator?
Measure net wall area and use the installed face dimensions of the brick/block plus the intended joint thickness. Those entries form the basis for estimating concrete or masonry block quantity for a wall.
Why should I check unit size and joint thickness in the Block Calculator?
In the Block Calculator, errors in unit size and joint thickness can materially affect the result. Concrete blocks are much larger than bricks, so small changes in the face module or joint thickness materially change units per wall area. Use the exact block size.
How should I use the Block Calculator result when ordering blocks?
Round up to whole blocks and add allowance for cuts/breakage. Lintels, bond beams, special blocks and structural reinforcement are not included in a basic face-count calculation. That is the practical way to carry the Block Calculator result into the next step.