Concrete block fill calculator
Use the void volume for the cells you actually plan to fill.
Formula
Volume = blocks × void volume × (1+extra/100); bags = ceil(volume / bag yield)
Net void volume per block: 0.2 ft³ · Wet yield per bag: 0.4 ft³ · Grout volume ≈ (100)×(0.2 ft³ × 28.31684659 L/ft³)×(1+(5)÷100)÷1000 · Cubic feet ≈ (0.5946537784)÷0.3048^3 · Whole bags ≈ ceil(((0.5946537784)×1000÷(0.4 ft³ × 28.31684659 L/ft³))×(1-8.881784197001252e-16))
How to use
- Enter the number of blocks being filled.
- Enter net fill per block and wet yield per bag.
- Set allowance and read grout volume and bags.
Examples
- 100 blocks at 6 L each need 0.6 m³, or 50 bags yielding 12 L.
Frequently asked questions
Is fill volume standard?
No. Get it from the manufacturer for the block and selected cells; the default is illustrative.
Are bond beams included?
No. Add horizontal cavities separately and account for reinforcement displacement.
Can any concrete fill the cells?
The tool estimates quantity only. Use the grout specified for the masonry system.
Sources
Updated: