Unit Converter
Convert length, mass, temperature, volume, energy, and more.
In Mile (mi).
To convert between units, multiply the value by the ratio of the two units relative to a shared base — for example meters for length or kilograms for mass. Temperature is the exception: Celsius, Fahrenheit, and Kelvin have different zero points, so you must add an offset as well as scale.
One converter, ten categories
Pick a category, choose your units, and the conversion happens as you type. Every unit maps to a category base unit — meters for length, kilograms for mass, joules for energy — so any pair converts accurately, including the awkward ones like Fahrenheit to Kelvin or kilowatt-hours to electronvolts.
- 1 Choose the measurement category. Select length, mass, temperature, volume, area, speed, time, energy, pressure, or digital storage — each category groups the units that convert to one another.
- 2 Enter the amount and pick the “from” unit. Type the value you have and choose the unit it is measured in, such as miles, kilograms, or °C.
- 3 Pick the “to” unit. Choose the unit you want the result in; it must belong to the same category as the “from” unit.
- 4 Read the converted value. The tool converts your value to the category base unit and then to the target, so the result equals your amount times the ratio between the two units.
- 5 Note the exception for temperature. Celsius, Fahrenheit, and Kelvin have different zero points, so the converter applies the full formula — a scale plus an offset — instead of a single ratio.
Common conversion factors
Internationally defined values; many are exact by definition (for example 1 inch = 0.0254 m).
| Convert | Factor | Reverse |
|---|---|---|
| 1 mile (mi) | = 1.609344 km | 1 km = 0.621371 mi |
| 1 inch (in) | = 2.54 cm | 1 cm = 0.393701 in |
| 1 kilogram (kg) | = 2.204623 lb | 1 lb = 0.453592 kg |
| 1 ounce (oz) | = 28.349523 g | 1 g = 0.035274 oz |
| 1 liter (L) | = 0.264172 US gal | 1 US gal = 3.785412 L |
| 1 mile/hour (mph) | = 1.609344 km/h | 1 km/h = 0.621371 mph |
Temperature is different — it has an offset
Most conversions are a single multiplication. Temperature is not: the Celsius, Fahrenheit, and Kelvin scales start at different zero points, so you have to shift as well as scale. That is why the converter applies the full formulas rather than one factor.
0 °C = 32 °F = 273.15 K; 100 °C = 212 °F = 373.15 K
Metric, imperial, and the units that trip people up
US vs imperial volume. This tool uses US gallons, quarts, and fluid ounces. The UK (imperial) gallon is larger — about 4.546 L versus the US 3.785 L — so check which system a recipe or spec means before converting.
Mass vs weight. In everyday use kilograms and pounds are treated as interchangeable units of how much something weighs. Strictly, kilograms measure mass and pounds-force measure weight, but for converting body weight or groceries the factor 1 kg = 2.205 lb is exactly what you want.
Decimal vs binary storage. A megabyte (MB) is 10⁶ = 1,000,000 bytes, while a mebibyte (MiB) is 2²⁰ = 1,048,576 bytes. Drives are advertised in decimal units and memory is measured in binary ones, which is why a “500 GB” drive shows up as roughly 465 GiB in your operating system. When a result is too large or small to read comfortably, the scientific notation converter can put it in standard form, and the number base converter handles binary, octal, and hex directly.