Enter your wall opening size, choose the block size, joint gap, and allowance. This tool estimates how many blocks you should order.
Measure the vent-block section only (exclude columns if needed).
Use finished height where blocks will be installed.
Thickness is for specification only (it does not change the quantity calculation).
Mortar/spacing gap between blocks. Typical: 3–8 mm.
Extra for cutting, breakage, tolerance. Usually 7–10%.
Auto chooses the better fit.
Wall area
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Blocks per m² (estimated)
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Total blocks to order (incl. allowance)
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How this estimate works
Enter your dimensions and click Calculate.
Important: This is an estimator using “module size” = block size + joint gap.
Allowance is recommended because real installation requires cutting and handling (especially for edges and corners).
