Updated
Using Concrete block fill calculator
Calculate fill volume from block count and the measured empty core dimensions.
Volume = blocks × cores per block × core area × height. Core area and height must use compatible squared and linear units. Use actual manufacturer core geometry; nominal block sizes do not determine void volume.
A worked example
Example inputs: number of blocks = 100, open cores per block = 2, clear area of one core = 0.01, core height = 0.2, extra allowance (%) = 10. Core-fill volume = 0.4.
Before you use the result
Volume = blocks × cores per block × core area × height. Core area and height must use compatible squared and linear units. Use actual manufacturer core geometry; nominal block sizes do not determine void volume.
Example results for number of blocks
These examples use Open cores per block: 2; Clear area of one core: 0.01; Core height: 0.2; Extra allowance (%): 10. They are reference calculations, not recommended settings.
| Number of blocks | Core-fill volume |
|---|---|
| 50 | 0.2 |
| 100 | 0.4 |
| 200 | 0.8 |
Cite this page
ToolOctopus. “Concrete block fill calculator.” Updated 2026-09-26. https://tooloctopus.com/concrete-block-fill-calculator.
Add an access date if your instructions require one.
Citation formatting uses citeproc-js by Frank Bennett and Citation Style Language styles. Licence and source code.