How it works
Volume counts unit cubes filling the box; multiplication gives that count for orthogonal edges.
Formula
V = length × width × height
How to use Volume of a Rectangular Prism Calculator
- Enter three mutually perpendicular edge lengths.
- Calculate cubic volume.
- Use with cube tool when all three edges match.
Worked examples
Concrete numbers and cases you can check against the tool above.
Aquarium 30×12×18 in
V = 6480 in³; divide by 231 for approximate US gallons (~28 gal).
When to use Volume of a Rectangular Prism Calculator
Shipping, aquariums, and room air volume are box math. It generalizes the cube when edges differ.
Common use cases
- Cargo volume in a shipping container.
- Soil for a raised bed box.
- GPU voxel grid cell counts in 3D grids.
Inputs and outputs
- Length, width, height in one unit system
Privacy
This tool runs entirely in your browser. Your data never leaves your device — nothing is uploaded to our servers.
Frequently asked questions
- Is order of dimensions important?
- No — the product is commutative.
- Internal vs external dimensions?
- Use interior dimensions for capacity; subtract wall thickness if measuring outside.
- L-shaped rooms?
- Split into multiple boxes and add volumes.