Unit Converter
Length, weight, temperature, volume, area, speed and data size.
About the unit converter
Eight categories β length, weight, temperature, volume, area, speed, data and time β each converting between metric and imperial units instantly. Beneath the main result, every unit in the category is listed at once, so you can see the whole picture rather than converting one pair at a time. Click any row to copy it.
Conversions worth committing to memory
- 1 inch = 2.54 cm exactly (this is the definition, not an approximation)
- 1 foot = 30.48 cm Β· 1 mile = 1.609 km
- 1 kg = 2.205 lb Β· 1 stone = 6.35 kg
- Β°C to Β°F: multiply by 1.8 and add 32. The two scales meet at β40Β°.
- 1 litre = 1.76 UK pints = 2.11 US pints β UK and US pints differ by about 20%, which catches out a lot of recipes
- 100 km/h = 62 mph
Why data sizes have two sets of units
A kilobyte is 1,000 bytes, but a kibibyte is 1,024. Storage manufacturers use the decimal units; operating systems have historically used the binary ones while labelling them with decimal names. That is why a "1 TB" drive shows up as about 931 GB in Windows β nothing is missing, the two are just counting differently. Both sets are listed separately here so you can see the gap.
Frequently asked questions
How do I convert Celsius to Fahrenheit?
Multiply by 1.8 and add 32, so 20Β°C is 68Β°F. Temperature is the one conversion that is not a simple ratio, because the two scales have different zero points.
How many pounds is a kilogram?
2.20462 pounds. A kilogram is defined as exactly 0.45359237 of a pound, so the conversion is exact rather than approximate.
Why is a UK pint different from a US pint?
They come from different historical gallon definitions. A UK pint is 568 ml and a US pint is 473 ml β about 20% smaller. Both are listed separately in the volume category.
Why does my 1 TB drive show as 931 GB?
The manufacturer counts 1 TB as a trillion bytes, while the operating system divides by 1,024 at each step. Nothing is lost β it is the same bytes described in different units.