Calculator
Aerated concrete block calculator
Calculates masonry volume and an estimated block count from wall dimensions, openings, block size, wall thickness and allowance.
Online calculation
Enter dimensions
Result
Result
Your result will appear here after calculation.
Calculation formula
Wall area = length × height; masonry volume = net area × wall thickness; blocks = ceil(masonry volume ÷ ((block length + joint) × (block height + joint) × block width)).
Example: For a 10 × 2.7 m wall without openings, 300 mm wall thickness and 600 × 200 × 300 mm blocks, the estimate is about 221 blocks before allowance.
Frequently asked questions
Why is wall thickness needed?
If the wall is thicker or thinner than the block width, face area alone is not enough. Masonry volume accounts for the full wall thickness.
Can I subtract openings?
Yes. Enter their combined area. For a complex wall, also check lintels, reinforcement and cutting against the working layout.