What does this tool do?
A nominal 8 × 8 × 16 in concrete block covers 0.89 sq ft of wall face, so a square foot needs about 1.125 blocks. This calculator scales that to the wall area, adds a breakage allowance and estimates mortar volume.
The Formula
Blocks = ⌈Wall area × 1.125 × (1 + Waste ÷ 100)⌉Frequently Asked Questions
How many concrete blocks per square foot?
A nominal 8 × 8 × 16 in block covers 0.89 sq ft, so a square foot needs about 1.125 blocks.
How much mortar does a block wall use?
Plan on roughly 0.03 cu ft of mortar per block, or a bag of mortar mix for every 20–25 blocks.