### Units

#### Introduction to Units

The Units program converts quantities expressed in various scales to their equivalents in other scales. The units program can handle multiplicative scale changes as well as nonlinear conversions such as Fahrenheit to Celsius or wire gauge.

The units are defined in an external data file. You can use the extensive data file that comes with this program, or you can provide your own data file to suit your needs. You can use the program interactively with prompts, or you can use it from the command line.

Units acts as a general calculator for units. You can add, subtract, multiply and divide units. You can raise units to integer powers and you can take roots of units. Operations can be grouped using parentheses.

#### Examples

Two simple conversion examples:

```    You have: mile
You want: km
* 1.609344
/ 0.62137119

You have: furlongs per fortnight
You want: m/s
* 0.00016630986
/ 6012.8727
```

A calculation involving roots of units:

```    You have: (400 W/m^2 / stefanboltzmann)^(1/4)
You have:
Definition: 289.80882 K
```

Temperature differences are converted using the syntax shown above with unit names like degC and degF. But conversion of absolute temperatures requires a different syntax:

```    You have: tempF(45)
You want: tempC
7.2222222
```

Units can be found on http://ftp.gnu.org/gnu/units/ [via http] and ftp://ftp.gnu.org/gnu/units/ [via FTP]. It can also be found on one of our FTP mirrors.

#### Documentation

The full manual is available in various formats. You may also find more information about Units by looking at /usr/doc/foo/ or /usr/local/doc/foo/ or by looking at man pages (man foo at the shell prompt) on your system.

#### Maintainer

Units is currently being maintained by <adrian@cam.cornell.edu>. If you wish to send a bug report, a feature request, or simply to share your thoughts about GNU units, please write to <adrian@cam.cornell.edu>.