Concrete volume & material calculator
Volume for a slab, beam, column or footing — then cement, sand, aggregate and water for the grade you are pouring. Change the dry volume factor or the mix ratio and every number updates.
Dry volume = Wet volume × factor
Cement = Dry × (1 ÷ parts) × 1440 kg/m³
Mix ratio in use: 1 : 1.5 : 3 · wet volume also — cft · sand — cft (— kg) · aggregate — cft (— kg)
How this calculator works
Volume comes straight from the member's geometry. Materials come from the nominal mix ratio and one correction — the dry volume factor — which accounts for the air voids that disappear when the mix is compacted.
- Wet volume = the member's dimensions, multiplied by the number of members.
- Dry volume = wet volume × 1.54 (editable; 1.52–1.57 are all in normal use).
- Cement volume = dry volume × cement's share of the total parts, converted to mass at 1440 kg/m³ and divided by 50 for bags.
- Sand and aggregate follow the same share-of-parts split.
- Water = cement mass × the water–cement ratio.
Sand is converted at 1600 kg/m³ and coarse aggregate at 1500 kg/m³. Those are typical loose bulk densities — if your supplier quotes different figures, the volumes are the numbers to trust.
Read the full guide: Cement, Sand & Aggregate for M20: Quantities per Cubic Metre
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