Unit Conversion Reference

The world uses two major measurement systems: the Metric system (SI — Système International) used by most countries globally, and the Imperial/US Customary system used primarily in the United States, Myanmar, and Liberia. Engineers, scientists, and international travellers frequently need to cross-convert between them.

Length Conversions

The base SI unit is the metre. Common conversions: 1 kilometre = 0.621371 miles; 1 metre = 3.28084 feet; 1 inch = 2.54 centimetres; 1 nautical mile = 1.852 kilometres.

Weight Conversions

The base SI unit is the kilogram. Common conversions: 1 kilogram = 2.20462 pounds; 1 pound = 16 ounces; 1 metric tonne = 1,000 kilograms = 1.10231 US short tons.

Temperature Conversions

Three scales are in common use: Celsius (°C) used internationally; Fahrenheit (°F) used in the US; and Kelvin (K) used in science. Formulas: °F = (°C × 9/5) + 32; K = °C + 273.15.

Volume Conversions

The base SI unit is the litre. Common conversions: 1 US gallon = 3.78541 litres; 1 UK gallon = 4.54609 litres; 1 US cup = 236.588 mL; 1 fluid ounce = 29.5735 mL.

Data Storage

Digital storage is measured in binary (powers of 2) or decimal (powers of 10). 1 kibibyte (KiB) = 1,024 bytes; 1 kilobyte (KB) = 1,000 bytes. This tool uses the common decimal convention where 1 GB = 1,000 MB.