Unit Converter
Type a value and its unit and get every other unit in that category at once, which is more useful than picking a target from a dropdown. Temperature is handled as an offset rather than a ratio, imperial and US liquid measures are listed separately, and data size covers both the SI and the binary prefixes.
The conversion table follows this. With nothing typed, the base unit is used.
Lower it for everyday figures; extra decimals on a conversion do not mean extra accuracy.
How unit converter works
- Choose a categoryData size, length, mass, temperature, time, speed, area or volume.
- Type a value and a unit100 km/h, 20 C, 1.5 GB, or a bare number for the base unit.
- Read the whole tableEvery unit in the category, with the conversion factors and the caveats underneath.
What you get
Convert length, mass, temperature, speed, area, volume, time and data size. Everything happens inside this page: the file is read by your browser, transformed in memory and handed straight back to you as a download. There is no upload queue, no waiting for a server, and nothing left behind when you close the tab.
Supported formats
This tool works on text you paste or type, so there is no file format to worry about. Nothing you type is sent anywhere.
Limitations, stated up front
- Months and years use fixed averages — 30.4375 and 365.25 days — which is wrong for any particular calendar date.
- Imperial and US units are both listed but never reconciled. A “gallon” is ambiguous, and the table says which one it is showing.
- No currencies, no fuel economy expressed as distance per volume, and no cooking measures that vary by recipe.
Frequently asked questions
Why show every unit rather than one answer?
Because you rarely know which unit the other system wants. Converting to a single target means a second round trip every time the target changes; showing the whole table means the value you need is already there, and a quick comparison between them is possible at a glance.
Which pint is in the volume table?
Both, named. The US liquid pint is 473 mL and the imperial pint is 568 mL, so the same word is a fifth larger in Britain. The same applies to fluid ounces, cups, quarts, gallons and tablespoons. Neither is the “right” one; the correct answer depends on which side of the Atlantic the recipe came from.
Why is a month not listed exactly?
Because it is not. Months run from 28 to 31 days and years from 365 to 366, so a month cannot be a fixed number of seconds. Furtu uses 30.4375 days for a month and 365.25 days for a year and says so in the note under the table, because a number with a stated assumption is more useful than no number.
Which definition of an inch is used?
The international one: exactly 25.4 mm, agreed in 1959. The US survey inch, still used in some surveying, is very slightly different, and the difference accumulates over long distances. The imperial foot here is 0.3048 m exactly.
Is my measurement uploaded?
No. Conversion is local arithmetic. Nothing about a measurement is transmitted.