UDUNITS
The Unidata units library supports conversion of unit specifications between formatted and binary forms, arithmetic manipulation of unit specifications, and conversion of values between compatible scales of measurement.
UDUNITS Introduction and Use
The Unidata units library, UDUNITS, supports conversion of unit specifications between formatted and binary forms, arithmetic manipulation of unit specifications, and conversion of values between compatible scales of measurement.
A unit is the amount by which a physical quantity is measured. For example:
 Physical Quantity Possible Unit time weeks distance centimeters power watts
The UDUNITS package also contains an interactive utility, udunits, which has two modes. In one mode, both an input and output unit specification are given, causing the utility to print the conversion between them:

You have: inch
You want: cm
cm = inch*2.54
cm = inch/0.393701

You have: (15 lbs force/in)^2
You want: atm2
atm2 = (15 lbs force/in)^2*0.995719
atm2 = (15 lbs force/in)^2/1.0043

You have: celsius
You want: fahrenheit
fahrenheit = celsius*1.8 + 32
fahrenheit = celsius/0.555556 + 32

In the other mode, only an input unit specification is given. This causes the utility to print the definition -- in standard units -- of the input unit:

You have: fahrenheit
You want:
Definition: "0.555556 kelvin @ 255.372"

You have: geopotential meters
You want:
Definition: "9.80665 meter2 second-2"

Further information on this package can be found in the C manual page or FORTRAN manual page, the associated utility manual page, or the perl extension manual page.

 UDUNITS News and Announcements See the package's release notes file.

 UDUNITS Availability The latest release is available from the Unidata downloads page.

 UDUNITS Installation See the package's INSTALL file. • Builds on Other Platforms • Known Problems • Supported Units • IDL Interface

 UDUNITS Support • Browse the UDUNITS support archives • Browse the netCDF support archives • Browse the netcdfgroup mailing list archives Questions or comments can be sent to Unidata UDUNITS Support