About this calculator
International shipping documents rarely stick to one system of units. Container specifications are quoted in feet and inches, US buyers ask for weights in pounds, bulk freight is fixed per long ton, and the packing list from an Indonesian factory is in centimetres and kilograms. A single conversion slip, such as assuming a "ton" is always 1,000 kg or treating a US gallon like an imperial one, is enough to make the weights on the B/L, the invoice and the VGM disagree.
This converter uses the exact international definitions: 1 inch = 25.4 mm, 1 foot = 0.3048 m, 1 pound = 0.45359237 kg, 1 short ton = 907.18474 kg, 1 long ton = 1,016.0469088 kg, 1 US gallon = 3.785411784 litres and 1 UK gallon = 4.54609 litres. There are three groups: length (mm, cm, m, in, ft, yd), mass (g, kg, t, lb, oz, short ton, long ton) and volume (cm³, L, m³, in³, ft³, US gal, UK gal).
Type one value and every unit of the same group is shown at once, so you do not have to convert back and forth. Conversions only work within a group; turning volume into weight needs the density of the goods, so use the chargeable weight or stowage factor calculator for that. Results are rounded for display, while the calculation itself keeps full precision.
Worked example
A forwarder preparing a quotation for a US buyer needs to align units:
- 1 in × 2.54 = 2.54 cm
- 40 ft × 0.3048 = 12.192 m (external length of a 40' container)
- 1,000 kg ÷ 0.45359237 = 2,204.62 lb
- 1 m³ ÷ 0.028316846592 = 35.3147 ft³
With these exact factors, weights and volumes on the invoice, packing list and B/L stay consistent.
How to use it
Choose the quantity
Pick length, mass or volume depending on the figure you need to convert.
Enter the value and its unit
Type the number and choose the unit it is in, for example 40 ft, 1,000 kg or 1 m³.
Read the result table
Every other unit in the same group appears at once, with precise figures you can copy into your documents.