Free construction calculator · Metric and imperial
Blockwork Quantity Calculator
Estimate blocks required from wall dimensions, openings, block size, mortar-joint thickness, and waste allowance.
Inputs
Enter measured dimensions
Formula and assumptions
Blocks = net wall area ÷ nominal block face area; order quantity = blocks × (1 + waste allowance)
Use measured dimensions from the latest approved information. Check deductions, laps, allowances, material modules, supplier constraints, and rounding rules before ordering or certifying quantities.
The result is an estimate for planning and checking. It does not replace a coordinated quantity takeoff, temporary-works design, structural design, geotechnical assessment, or project-specific engineering review.
Questions
Are mortar joints included in the block count?
The calculator uses the nominal module formed by the block face plus the selected joint thickness.
Should door and window openings be deducted?
Yes. Deduct measured openings, then consider whether small openings, cuts, returns, and piers require a project-specific adjustment.