Materials & quantities
Concrete Slab Volume Calculator
Calculate slab volume from length, width, and depth in consistent units.
Use this for an early volume check and confirm structural design, reinforcement, and ordering with a qualified professional.
What the result means
The result is geometric volume in cubic units matching the dimensions. It is not a structural plan or an order guarantee.
The formula
Length * width * depth
Results are displayed to at most two decimal places. Calculations use the unrounded inputs.
A worked example
Put the formula to work
- Length (metres)
- 5
- Width (metres)
- 4
- Depth (metres)
- 0.1
Slab volume: 2
A five by four metre slab at 0.1 metre depth has a volume of two cubic metres.
How to use this calculator
- Measure the planned footprint.
- Convert every dimension to one unit.
- Enter the average depth.
- Confirm excavation, reinforcement, mix, and ordering requirements separately.
Why this number matters
Consistent units make the basic volume assumption easy to check before a project is priced.
Input definitions
- Length (metres)
- Use the same unit for all dimensions.
- Width (metres)
- Use the same unit for all dimensions.
- Depth (metres)
- Average slab depth in the same unit.
Assumptions and limitations
- Irregular ground, thickened edges, waste, and ordering minimums are excluded.
- Not a professional structural plan or engineering advice.
Methodology
The default result and worked example use the same calculation functions as the interactive tool. The formula cannot verify the quality or scope of your source data.
Read our calculation methodology
Last updated .