Enter dimensions
Results
Enter your dimensions above and the results appear here.
About the Cuboid Calculator
The cuboid calculator is a free online tool: volume, surface area and diagonal of a box. Enter length (l), width (w) and height (h) and the results update instantly, alongside a labelled diagram so you always know which measurement goes where.
Choose your input unit (mm, cm, m, km, in, ft or yd) and optionally show the results in a different one: lengths, areas and volumes are converted correctly. Every answer shows the formula behind it, and the calculation runs in your browser, so nothing is uploaded.
Cuboid Calculator example
Length (l) = 8 cm
Width (w) = 5 cm
Height (h) = 4 cmVolume = 160 cm³
Total surface area = 184 cm²
Lateral surface area = 104 cm²
Space diagonal = 10.247 cm
Base area = 40 cm²How to use the Cuboid Calculator
- Pick the unit your measurements use. All dimensions must share the same unit.
- Enter length (l), width (w) and height (h). Focus a field to highlight the matching label on the diagram.
- Read the results as you type. The largest card is the main answer; the others are the related measurements.
- Copy a single value, copy everything, or share a link that keeps your inputs.
Cuboid Calculator FAQ
What formulas does the cuboid calculator use?
V = l·w·h; SA = 2(lw + lh + wh); d = √(l² + w² + h²).
Can I use different units?
Yes. Pick the input unit and, if you like, a different output unit. Area results are shown in squared units and volumes in cubed units.
Is this cuboid calculator free and private?
Yes. It is free with no sign-up, and calculations happen on your device, so your numbers are never sent to a server.
More 3d solids
Sphere CalculatorHemisphere CalculatorCylinder CalculatorCone CalculatorCone Frustum Calculator