Use nominal block face dimensions, wall area and waste to create a planning unit count.
Results use your measurements and editable assumptions. Verify product coverage, density, waste and order rounding with the supplier before purchasing.
Blocks = net wall area ÷ nominal block face area, rounded up.
BuildCalc converts measurements to a consistent internal unit, applies your project geometry and only then adds the selected waste allowance. Packaging quantities are rounded up because partial bags, blocks or boxes usually cannot be ordered.
Concrete block is often described by nominal dimensions that include the mortar joint. Measure the wall face, subtract openings and confirm whether your entered unit size is actual or nominal. Bond beams, lintels, corners and other specialty units need a separate count.
A wall with no openings has 160 square feet of face area. A nominal 16 × 8 in block module covers about 0.889 square foot, giving 180 blocks before waste. A 7% allowance rounds the plan to 193 blocks.
Those are nominal dimensions and generally include the mortar joint. Actual unit dimensions are smaller; confirm the module used by the selected product.
No. The result is a general face-unit count. Specialty units, reinforcement, grout and mortar require a project-specific takeoff.
Published and maintained by EasyTool.me. Review the calculation methodology, verify product-specific values with the supplier, and report reproducible corrections. Last materially reviewed August 16, 2026.