How to use the concrete volume calculator
- Length (m): Slab length in meters.
- Width (m): Slab width in meters.
- Thickness (cm): Slab thickness in centimeters.
- Extra allowance (%): Additional volume allowance.
- Select Calculate to see the result. Change any input and calculate again to compare.
Worked example
A 5 × 4 m slab, 10 cm thick, is 2 m³ or 2.2 m³ with 10% allowance.
Formula and assumptions
Length × width × thickness = volume.
Volume only. Does not determine structural thickness, reinforcement, mix strength or code compliance.
Common questions
Why might my result differ from another estimate?
Volume only. Does not determine structural thickness, reinforcement, mix strength or code compliance. Keep the same inputs and rounding when comparing tools.
Are my entries saved?
No. Calculations run on your device. Reloading or closing this page may clear your entries.