Practical estimates. Clear assumptions.
Concrete Block Calc publishes this free calculator to help you estimate concrete or cinder blocks for a rectangular wall before discussing an order with a supplier.
What the tool does
Enter wall dimensions, nominal block face size and separate openings. Choose a waste allowance, then add your own block price and pallet size if you want a material cost estimate. You can use imperial or metric measurements, download a CSV estimate, print it, or share a link containing the inputs.
How we approach accuracy
The calculator uses exact decimal arithmetic and explicit input limits. Its calculation logic has been checked against independent examples and boundary scenarios. Its area model still cannot replace a block-by-block layout, supplier purchase list or structural design. The calculation method and worked examples explain those limits.
Publisher and corrections
This website is published under the Concrete Block Calc brand at concreteblockcalc.com. Questions or corrections can be sent through the contact page. Include the measurements, block size, waste allowance, result shown and what you expected so the issue can be reproduced.
Calculation method reviewed 18 October 2026. See how calculator inputs and shared links are handled.