Concrete Mix Ratio Calculator
Calculate the quantities of cement, sand, and coarse aggregate required for a given concrete mix ratio and volume.
Formula
Dry Volume = Wet Volume × 1.54
The factor 1.54 accounts for the reduction in volume when dry materials are mixed with water (voids fill, particles compact). This is the standard industry multiplier.
Volume of each material = (Ratio Part / Total Parts) × Dry Volume × (1 + Wastage%/100)
Mass of each material = Volume × Bulk Density
Cement Bags = Cement Mass (kg) / 50
Water = Cement Mass × Water-Cement Ratio (default 0.50)
Assumptions & References
- Dry-to-wet volume conversion factor of 1.54 is standard per IS 10262 and ACI 211.1.
- Default cement bulk density: 1440 kg/m³ (IS 456:2000).
- Default sand bulk density: 1600 kg/m³; aggregate: 1550 kg/m³.
- Standard cement bag weight: 50 kg (India/UK standard).
- Water-cement ratio of 0.50 is a typical starting point for M15–M20 mixes; adjust for workability and exposure conditions per IS 456 / ACI 318.
- Mix grades: M7.5 (1:4:8), M10 (1:3:6), M15 (1:2:4), M20 (1:1.5:3), M25 (1:1:2) per IS 456:2000.
- Results assume dry aggregates; deduct free moisture from water if aggregates are wet.
- Wastage factor accounts for spillage and over-ordering; 5–10% is typical for site work.