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Block Fill Calculator
Estimate grout to fill CMU block cores.
How the block fill calculator works
A standard 8×8×16 CMU has ~0.087 ft³ of core volume (both cells). Multiply block count by core volume by the percentage of cells you're filling to get total grout volume.
Frequently asked questions
How much grout for a CMU wall?
Fully grouted 8 in CMU takes about 1 yd³ per ~310 blocks. Partially grouted (every other cell) roughly halves that.
What mix is used for block fill?
Fine-aggregate grout with 8–11 in slump, ~2000–3000 psi. Sold pre-bagged as 'core fill grout' or 'block fill'.
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