Concrete Calculator
Estimate a rectangular concrete pour in cubic metres, cubic yards and cubic feet.
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How to use it
- Replace the examples with your measurements or exact product coverage.
- Choose the unit beside each input. Changing the unit converts the existing value.
- Choose any allowance deliberately, calculate, and check the purchase units.
Formula
V = length × width × depth; order volume = V × (1 + extra/100).
Worked example
5 m × 4 m × 0.1 m = 2 m³; with 10% extra, 2.2 m³.
Common mistakes and limits
Quantity only. This does not select slab thickness, reinforcement, strength or foundation design.
Do not add allowance twice. Example coverage, density and prices are illustrative, not a specification for your project.
Frequently asked questions
Is cement the same as concrete?
No. This estimates mixed concrete volume, not the quantity of cement powder or a concrete mix design.
Does the extra allowance change the slab dimensions?
No. It increases the purchase target; the measured net slab volume is shown separately.
Are my measurements sent to a server?
These calculations run in your browser. This calculator does not send the input values to our server. Normal page requests can still appear in hosting logs.
Measurement guides
- How to measure a rectangular concrete slab
- Concrete bag weight is not the same as concrete yield
- Cubic metres, cubic yards and cubic feet: a practical conversion
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