About this calculator
AAC blocks are laid with thin adhesive (about 3 mm); concrete blocks with mortar (about 10 mm).
How to use it
- Choose feet or metres and enter the dimensions.
- Choose the mix or materials.
- Read the quantities to order.
The formula
Blocks = wall area ÷ ((block length + joint) × (block height + joint))
- joint
- adhesive or mortar thickness
Worked example
A 20 × 10 ft wall with 600 × 200 mm AAC blocks
- Each block with a 3 mm joint covers 0.603 × 0.203 m.
- 8.17 blocks per m² × 18.58 m² = 152 blocks.
- With 5% wastage: 160 blocks.
What the result means
AAC blocks are light and insulate well, but need the right adhesive and curing.
Assumptions
- A plain wall without openings.
Limitations
- Deduct doors and windows from the wall size.
Frequently asked questions
How many AAC blocks per sq ft?
About 0.76 for 600 × 200 mm blocks with thin joints.
Which is better, AAC or brick?
AAC is lighter and faster; bricks are familiar and easy to repair.
Do AAC walls need plaster?
Usually yes, a thin coat.
Last reviewed on 3 October 2026. Found a mistake? Tell us.