Cement Calculator
For site-mixed concrete: enter the wet volume you need and the mix ratio. The calculator applies the dry-volume factor and splits cement, sand and gravel quantities. Bag size is configurable.
Cement Calculator
Concrete & Construction
ft³
Cement bags
7× 50 kg
Sand
15.4 ft³ · 0.436 m³
≈ 2 lb at 1.6 t/m³
Gravel
30.8 ft³ · 0.872 m³
≈ 3 lb at 1.5 t/m³
Dry volume
53.9 ft³ · 1.526 m³
wet 35 ft³ × 1.54
Calculation breakdown
- 1Dry volume:
0.991 × 1.54 = 1.526 m³ - 2Mix split:
1:2:4 → cement 0.143, sand 0.286, gravel 0.571 - 3Cement volume:
0.218 m³ ÷ 0.0347 m³ = 7 bags
Dry volume = Wet volume × 1.54 (voids factor).
Part volume = Dry volume ÷ (C : S : G sum).
Cement bags = Cement volume ÷ bag volume (50 kg bag ≈ 0.0347 m³ · 94 lb bag = 1 ft³).