Unit Converter
A precise converter for everyday units across six categories — length, weight, temperature, volume, area and speed — in both directions.
Please enter valid values.
Result
How to use
- Pick a measurement category.
- Enter the value and choose the units to convert from and to.
- The result updates as you type; use the swap button to reverse the conversion.
Frequently asked questions
Which units are supported?
Length (mm to miles), weight (mg to tonnes), temperature (°C, °F, K), volume (ml to gallons), area (cm² to acres) and speed (km/h, m/s, mph, knots) — more than 40 units in total.
How accurate are the conversions?
Conversions use exact internationally-agreed factors (e.g. 1 inch = 25.4 mm exactly). Temperature conversions use the standard formulas between Celsius, Fahrenheit and Kelvin.
What is the difference between mass and weight?
Mass (kilograms) is the amount of matter; weight is a force that depends on gravity. Everyday converters treat kilograms and pounds as equivalent units, which is accurate anywhere on Earth.
Why is a US gallon different from a UK gallon?
The US gallon is 3.785 litres while the old imperial gallon is 4.546 litres. This converter uses US units, the standard in most online references.