🏗️ Concrete Calculator

Slab / Wall / Column (rectangular): Volume = Length × Width × Thickness Circular Pad / Cylinder: Volume = π × (Diameter/2)² × Depth = 0.7854 × Diameter² × Depth Footing (strip): Volume = Length × Width × Depth Always add 5–10% wastage to account for: - Formwork irregularities - Spillage during pouring - Honeycomb voids requiring extra fill

M20 Concrete (1:1.5:3 by volume): Dry volume = 1.54 m³ (accounting for voids) Cement = (1/5.5) × 1.54 = 0.28 m³ = 8.07 bags Sand = (1.5/5.5) × 1.54 = 0.42 m³ Aggregate = (3/5.5) × 1.54 = 0.84 m³ Water = 0.45 × (cement weight in kg) Sum of ratios: 1 + 1.5 + 3 = 5.5 Dry to wet volume factor: 1.54 M10: 1:3:6 → 4.8 bags cement/m³ M15: 1:2:4 → 6.2 bags cement/m³ M20: 1:1.5:3 → 8.1 bags cement/m³ M25: 1:1:2 → 11.1 bags cement/m³