Box volume tells you how much space a box holds or takes up. It is needed for storage planning, moving house, comparing box sizes and calculating shipping space. The formula is simple, but unit conversions trip people up. This guide shows how to calculate box volume in different units, with our free Box Volume Calculator.
The formula
Volume = Length × Width × Height
Use the same unit for all three dimensions.
Example
A box of 40 × 30 × 25 cm:
Volume = 40 × 30 × 25 = 30,000 cm³
Converting units
| Unit | Conversion | 30,000 cm³ equals |
|---|---|---|
| Litres | ÷ 1,000 | 30 L |
| Cubic metres (m³, CBM) | ÷ 1,000,000 | 0.03 m³ |
| Cubic feet | ÷ 28,317 | 1.06 cu ft |
| Cubic inches | ÷ 16.387 | 1,831 cu in |
Box in inches
A box of 16 × 12 × 10 inches = 1,920 cubic inches. Divide by 1,728 to get cubic feet: 1.11 cu ft.
Inner vs outer volume
Inner volume tells you capacity; outer volume tells you how much space the box takes in a truck or container. See inner vs outer box dimensions.
Common mistakes
- Mixing cm and mm (a 400 mm side entered as 400 cm gives a volume 1,000 times too big)
- Forgetting to cube the conversion factor (1 m = 100 cm, but 1 m³ = 1,000,000 cm³)
- Using cu ft to cm³ factor 28.3 instead of 28,317
Uses
- Shipping: volume in CBM decides freight space; see the CBM Calculator.
- Courier charges: volume divided by a divisor gives volumetric weight; see the Volumetric Weight Calculator.
- Storage: estimate how many boxes fit on a shelf or in a room.
For moving house, read moving box sizes and capacity.
Volume of other shapes
Not every package is a box. For a cylinder such as a tube or tin, volume = π × radius² × height. A tube 10 cm in diameter and 50 cm long holds 3.1416 × 5² × 50 = 3,927 cm³, about 3.9 litres. Couriers usually charge cylinders as if they were boxes of the same length, width and height, so a 10 × 10 × 50 cm box would be used for volumetric weight.
Frequently asked questions
How do I calculate the volume of a box?
Multiply length, width and height in the same unit.
How many litres is 30,000 cm³?
30 litres.
How do I convert cubic inches to cubic feet?
Divide by 1,728.