In short: A unit converter translates measurements between units of the same quantity — such as kilometers and miles, kilograms and pounds, or Celsius and Fahrenheit — using exact conversion factors.
About Unit Converter
Recipes in cups, a running pace in miles, a weather forecast in Fahrenheit, a hard drive in gibibytes — mixing measurement systems is part of daily life. Rather than hundreds of separate pages for every unit pair, this converter puts the common units of eight quantities in one place, converts in both directions as you type, and shows the value in every other unit at once.
Conversion factors use exact definitions where they exist (one inch is exactly 2.54 cm, one pound exactly 0.45359237 kg, one US gallon exactly 3.785411784 liters). Temperature uses the proper offset formulas rather than a simple factor. Digital storage distinguishes decimal units (kB, MB, GB, as used by drive makers) from binary units (KiB, MiB, GiB, as used by many operating systems).
How to use Unit Converter
- Choose the quantity, such as Length or Temperature.
- Enter a value and pick the units to convert from and to.
- Type in either box — the other updates instantly. Use ⇄ to swap units.
- Check the table to see the value in every unit of that quantity.
Examples
10 kilometers = 6.2137 miles.
180 °C = 356 °F (°F = °C × 9/5 + 32).
Frequently asked questions
Why does my 1 TB drive show about 931 GB?
Drive makers use decimal terabytes (1012 bytes), while Windows reports binary units: 1012 bytes is about 931 GiB, labeled “GB”.
Are US and UK gallons the same?
No. A US gallon is 3.785 L; an imperial (UK) gallon is 4.546 L. Both are listed separately.
How precise are the results?
Results are shown to up to 10 significant digits, using exact definitions for factors where they exist.
Is a ton the same everywhere?
No. A metric tonne is 1,000 kg, a US short ton 907.18 kg and a UK long ton 1,016.05 kg.
Updated November 2026 · Free, no signup · How we build and test tools