Ultimate Unit Converter

Write your expression (see the Examples button!) into the Input text field and press enter to perform the conversion, which is into basic SI by default, but you can fill the Target units field to specify an output unit (e.g. Torr into mbar).
Units are case sensitive! In the Reference you will find a comprehensive list.

UUC will perform dimensional analysis for you and if the Input & Target units are mismatched, you will get a warning.
This is often caused by a misunderstood unit symbol and collision with a different unit (e.g. you expect C to be degree Celsius, but C is reserved for coulomb, degree celsius is °C).
It can also be caused by wrong syntax (e.g. you expect mK to be metre times kelvin, but it's actually milikelvin, the correct syntax is m*K)

You might sometimes encounter rounding bugs, e.g. you expect 10000 but get something like 9999.99996 or 10000.0000004. It's caused by floating-point arithmetics, which is a fundamental principle of all electronic computations and it would be very difficult to circumvent. Sorry!

Note 1: The prefix "micro" is u, not μ, since it's easier to type...
Note 2: If you miss your favorite unit or constant and would like to see it here, you can contact me.
Note 3: If you have an idea how to enhance the application, you can contact me.
Note 4: If you are a programmer interested in the source code, see the Github repository.
Note 5: UUC handles temperature units as temperature difference, not absolute temperature. See °C in the Reference for details.

Continue by clicking on the CONVERTER button to get started or the Reference button to see what's supported.

You can write a unit here to filter the ones with same dimension (1 for dimensionless), or write _ to list constants:


Target units:


Basic examples:

min you don't have to type any number before units and it's regarded as 1. Here it converts 1 minute (to seconds by default)
6 kPa or 6kPa you can use standard SI prefixes before units. Spaces are entirely optional, all spaces are ignored
6.2 kJ or 6,2 kJ comma also works as a decimal point
12 ug*Hz / Pa you can multiply using *, divide using /. Using a space won't work!
-0.007 cm^7 * mV^-3/s0.5 you can raise to power by simply writing number after the unit or by using ^
l^0,333333 cube root can be only aproximate, sorry...
2e-12 kg you can use e... to express "times 10 to the ..."
2.99 EUR/kg currency conversion works too (basic unit is USD), exchange rates are downloaded every day from ECB using this public API.

Useful examples:

3500 min-1 → Hz conversion of RPM to Hz
3 _g*lb*ft → J foot-pound force to joule, _g is standard gravity. All constants in UUC are marked by _
kg*_g/cm^2 → psi kilogram force per square cm to psi (psi could also be written as lb*_g/in2 by the same logic)
lb*ft/s2 → N poundal to newton

Peculiar features:

UUC can be used for more than just conversion of units within the same dimension. Using built-in universal constants, it can perform simple calculations where one physical quantity is another one multiplied by one or several universal constants, e.g.:

yr*_c → m year times speed of light = lightyear (in metres). Although this is pointless, since lightyear itself is implemented as ly
T/_mu → Oe magnetic flux (B) in tesla to magnetic field (H) in oersted