How it works
Estimate concrete volume for a rectangular slab. This calculates material volume only and does not specify structural reinforcement.
Inputs and units
| Input | Example value | What to enter |
|---|---|---|
| Length | 5 m | Required unit: m. Must be greater than zero. |
| Width | 4 m | Required unit: m. Must be greater than zero. |
| Thickness | 10 cm | Required unit: cm. Must be greater than zero. |
| Extra allowance | 5 % | Enter the percentage as a number: for 15%, enter 15. Use a non-negative value. Allowed range: 0–100. |
Worked example
Show example inputs and results
This example is generated by the same calculation engine using the starting values in the form. Your own inputs produce your own result.
- Length
- 5 m
- Width
- 4 m
- Thickness
- 10 cm
- Extra allowance
- 5 %
Complete example results
- Concrete volume
- 2.1 m³
Reading the result
Convert measurements to the same unit and use the net area to cover. Replace any package, waste or efficiency input with your product information. A quantity estimate alone does not determine installation conditions.
Questions and answers
Can I use the example values for my own calculation?
The example values illustrate the calculation. Replace every input with your own information, especially dates, rates and the selected operation.
Why are some results rounded?
Results display up to 8 decimal places. Calculations use the unrounded values; very small values use scientific notation. JavaScript floating-point arithmetic can introduce tiny rounding differences.
Are my inputs sent to a server?
The calculator processes inputs in your browser. Its code does not send your values to a server.