Convert a quantity between compatible measurement units. Choose the measurement type first, then enter the value and the source and destination units.
A kilometre contains 1,000 metres: 2.5 km therefore equals 2,500 m. A unit conversion preserves the same quantity while changing its representation; it cannot turn distance into weight.
Check the unit on both sides of the conversion, especially when comparing metric and imperial values. Round only after the calculation if the final answer will be used in a form or document.
Temperature conversions involve an offset as well as a scale factor. Do not treat degrees Celsius to Fahrenheit like a simple length conversion.