Concrete Calculator
Calculate the volume of concrete required for slabs, footings, or columns.
Assumptions
Add 5-10% wastage to the calculated volume for practical ordering.
Concrete Volume
How to use the Concrete Calculator
- Choose the shape: rectangular slab, square footing or circular column.
- Enter the dimensions shown (length, width and thickness, or side and depth, or diameter and height).
- Click Calculate to get the concrete volume.
- Add 5–10% extra for spillage and uneven ground before ordering.
Formula used
Thickness and diameter are entered in centimetres and converted to metres in the calculation.
Worked example
Two examples
Slab 4 m × 3 m × 12 cm = 4 × 3 × 0.12 = 1.44 m³
Column 30 cm diameter, 3 m high = π × 0.15² × 3 ≈ 0.212 m³
Common concrete grades
For houses in India, M20 (nominal mix about 1:1.5:3) is typical for slabs, beams and columns, while M15 (1:2:4) is used for PCC and non-structural work. Higher grades like M25 and above are designed mixes. Once you know the volume, use the cement calculator to estimate cement bags, sand and aggregate for your chosen mix.
Tips for accurate results
- Residential roof slabs are commonly 100–150 mm thick.
- Ready-mix concrete is ordered in cubic metres; round up to the next 0.5 m³.
- For complex shapes, split them into simple rectangles and cylinders and add the volumes.
Frequently Asked Questions
Multiply by 35.31. 1.44 m³ is about 50.9 ft³.
Usually 5–10% extra to cover wastage and variations in depth.
No. Steel is estimated separately, typically as kg per cubic metre of concrete.
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Content reviewed by Vinod, Easy Smart Calculator · Last updated October 2026