Calculate the number of concrete blocks and amount of mortar needed for your wall project.
Wall Dimensions
ft
ft
in
%
Material Estimate
Enter dimensions to estimate materials
About this calculator
Overview
CMU (Concrete Masonry Unit) walls are a staple of durable construction. This calculator estimates the total number of blocks based on the surface area of your wall, accounting for the vertical and horizontal mortar joints that separate each block.
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Pro Tips
Always order at least 5-10% extra blocks to account for breakage during transport or cutting at corners.
A standard 3/8" (9.5mm) mortar joint is the industry default for most masonry work.
Stagger your blocks in a 'running bond' pattern for maximum structural integrity.
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Fun Facts
"Standard hollow concrete blocks are also known as breeze blocks in the UK or CMUs in the US."
"The actual size of a block is typically 3/8" smaller than its nominal size to account for the mortar joint."
"Concrete blocks are exceptionally fire-resistant and provide excellent soundproofing."
Formula: Number of Blocks = (Wall Area) / (Block Length × Block Height)
