Unit Converter

How to use

1. Choose what you are converting — length, weight, temperature and so on.
2. Enter a value and pick the units on each side.
3. The result updates as you type. Use swap to reverse the direction.
4. Copy the result when it is what you need.

Features

• Eight quantities: length, weight, temperature, data, area, volume, speed and time.
• Decimal and binary data units kept separate, so GB and GiB never get conflated.
• Exact factors — an inch is 2.54 cm and a pound is 0.45359237 kg, not rounded approximations.
• Accepts a comma as the decimal separator, as most of the world writes it.
• Runs entirely in your browser, with no network request per keystroke.

Frequently asked questions

Why is a 1 TB drive shown as 931 GB by my computer?

Because two different units share a name. Drive makers count a terabyte as 1,000,000,000,000 bytes; most operating systems divide by 1024 three times and call the result GB, when the correct name for that unit is GiB. 1 TB is 931.32 GiB. This converter keeps both, so you can see the difference rather than fall into it.

How exact are the conversions?

The factors are the defined ones, not rounded shorthand: one inch is exactly 2.54 cm, one pound is exactly 0.45359237 kg, one mile is exactly 1609.344 m. Results are shown to ten significant digits, which is well past what any measurement justifies.

Why does temperature work differently?

Because its scales do not share a zero. Converting 10 metres to feet is a multiplication; converting 10°C to °F is not, because 0°C and 0°F are different temperatures. Temperature is converted through kelvin, which is why -40 is the same number in both Celsius and Fahrenheit.

Is a year 365 days here?

No — 365.25 days, the average calendar year including leap years. It is what people mean by "a year" when converting from hours or days, and it is the value the Julian year is defined with.

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