Calculate exact quantities of cement, sand, and coarse aggregate for any volume of concrete. Covers M10 to M30 grades with dry volume correction factor.
M20 uses a 1:1.5:3 mix. For 1 m³: Dry volume = 1 x 1.54 = 1.54 m³. Cement = 1.54/5.5 x 1 x 1440 = 403 kg (8 bags). Sand = 1.54/5.5 x 1.5 x 1600 = 672 kg. Aggregate = 1.54/5.5 x 3 x 1500 = 1260 kg.
Multiply wet concrete volume by 1.54 to get dry material volume. This accounts for bulking of aggregates and voids between particles when dry materials are mixed with water.
M20 concrete (1:1.5:3) requires approximately 8 bags (403 kg) of 50kg cement per cubic metre of wet concrete.
M15, M20, M25 denote characteristic compressive strength in N/mm² after 28 days. M20 is minimum grade for RCC work per IS 456. M25 is used for columns, foundations, and water-retaining structures.
The water-cement ratio for M20 is 0.45 to 0.55. Lower ratios give stronger concrete. For M25, use 0.40-0.45. Higher ratios increase workability but reduce strength.
100 cubic feet = 2.83 m³. For M20: 2.83 x 1.54 / 5.5 = 0.793 m³ per part. Cement: 0.793 x 1440 = 1,142 kg (23 bags). Sand: 0.793 x 1.5 x 1600 = 1,903 kg. Aggregate: 0.793 x 3 x 1500 = 3,569 kg.