## GNU Units

GNU Units converts quantities expressed in various
systems of measurement to their equivalents in other systems of
measurement. Like many similar programs, it can handle multiplicative
scale changes. It can also handle nonlinear conversions such as
Fahrenheit to Celsius or wire gauge, and it can convert from and to sums of
units, such as converting between meters and feet plus inches.

Beyond simple unit conversions, GNU Units can be used as a
general-purpose scientific calculator that keeps track of units in its
calculations. You can form arbitrary complex mathematical expressions
of dimensions including sums, products, quotients, powers, and even roots
of dimensions. Thus you can ensure accuracy and dimensional consistency
when working with long expressions that involve many different units
that may combine in complex ways.

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 also use your
own data file to supplement the standard data file.

#### 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

Converting from a sum of units:

You have: 17 yards + 2 feet + 5 inches
You want: meter
* 16.2814
/ 0.06141978

Converting to a sum of units such as hours plus minutes or feet plus inches:

You have: 7 meters
You want: ft;in
22 ft + 11.590551 in

Converting a sixth of a (US) cup to common US measures:

You have: 1|6 cup
You want: usvol
2 tbsp + 2 tsp

### Downloading
Units

#### Source Distribution

Units
can be found on the main GNU ftp server:
http://ftp.gnu.org/gnu/units/
(via HTTP) and
ftp://ftp.gnu.org/gnu/units/
(via FTP). It can also be found
on the GNU mirrors;
please
use
a mirror if possible.

#### Windows Binary

A binary distribution for Windows is available at
http://ftp.gnu.org/gnu/units/windows/
(via HTTP) and
ftp://ftp.gnu.org/gnu/units/windows
(via FTP).

### Documentation

Documentation for
Units
is available online, as
is documentation for most GNU software. You may
also find more information about
Units
by running
*info units*
or
*man units*,
or by looking at
*/usr/share/doc/units/*,
*/usr/local/doc/units/*,
or similar directories on your system. A brief summary is available by
running *units --help*. The units definitions can
generally be found in */usr/share/units/*.

- Test releases
- Trying the latest test release (when available) is always
appreciated. Test releases of
Units
can be found at
http://alpha.gnu.org/gnu/units/
(via HTTP) and
ftp://alpha.gnu.org/gnu/units/
(via FTP).
- Maintainer
- Units
is currently being maintained by
Adrian Mariano
All general bug reports, feature requests or thoughts should go to him.
- The Windows binary distribution is maintained by
Jeff Conrad.

### Licensing

Units
is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free
Software Foundation; either version 3 of the License, or (at your
option) any later version.