What is a unit converter?

A unit converter translates a measurement from one system to another, such as inches to millimeters or pounds to kilograms. In shipping and fulfillment, conversions come up constantly: US carriers rate packages in inches and pounds, while international carriers, customs forms, and overseas suppliers typically use centimeters and kilograms. Our free unit converter handles length, weight, and volume in one place, so you can move between imperial and metric measurements without a spreadsheet.

How do you convert units of measurement?

Every unit conversion uses a fixed conversion factor. To convert a measurement, multiply the value by the conversion factor for the two units. For example, 1 inch equals exactly 25.4 millimeters, so a 10-inch carton is 10 × 25.4 = 254 mm.

  • To convert inches to millimeters, multiply inches by 25.4. To convert mm to inches, divide millimeters by 25.4 (or multiply by 0.03937).

  • To convert pounds to kilograms, multiply pounds by 0.4536. To convert kg to pounds, multiply kilograms by 2.2046.

  • To convert cubic feet to cubic meters, multiply cubic feet by 0.0283. To convert cubic meters to cubic feet, multiply by 35.3147. Cubic measurements matter most when planning pallets, containers, and warehouse storage.

What is the difference between metric and imperial measurements?

Imperial (US customary) units include inches, feet, ounces, pounds, and gallons. Metric units include millimeters, centimeters, meters, grams, kilograms, and liters. The United States ships primarily in imperial units, while most of the world, including the EU and UK, uses metric. Brands that sell internationally often need both: product listings, customs declarations, and carrier labels may each call for a different system.

Example: A 12 × 10 × 8 inch carton weighing 4 pounds measures 30.48 × 25.4 × 20.32 cm and weighs 1.81 kg. Its volume is 960 cubic inches, or about 0.56 cubic feet (0.0157 cubic meters).

Getting these numbers right protects your margins. A rounding error on carton dimensions can change your dimensional weight, your cartons per pallet, and what you pay to ship. For brands shipping into the US from abroad, we also support European and UK fulfillment.

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