How this calculator works
Estimate concrete masonry units for a wall including openings, joints and waste.
blocks = net wall area ÷ modular block face × (1 + waste%)
Masonry · Calculator
Estimate concrete masonry units for a wall including openings, joints and waste.
Estimate concrete masonry units for a wall including openings, joints and waste.
The calculator uses the following core relationship:
Estimating note: Actual material quantities can vary with site conditions, detailing, product dimensions, installation method, and waste.
A concrete block calculator estimates the number of blocks required for walls based on dimensions and block size.
Block size, openings and wall thickness affect final quantities.
Construction tip: Always verify measurements, material specifications and project conditions before purchasing materials.
Estimate concrete masonry units for a wall including openings, joints and waste.
The calculator uses inputs such as Wall width (m), Wall height (m), Openings area (m²), Block length (mm), and Block height (mm). Use values from your drawings, measurements, product data, or project specifications.
Use outputs such as Blocks to order, Before waste, and Net wall area for estimating and cross-checking. Before purchasing or construction, confirm the dimensions, units, waste factors, supplier packaging, and project specifications.
Continue your estimate with related Construction Calc Lab.