There are plenty of unit converters online, but sometimes it’s nice to have a desktop application handy. The unit types and formulas can all be customized if you want to dig into the included unit files and figure out how it works.
Note: I can’t guarantee all the conversions are 100% accurate. The conversion formulas were compiled from various sources and they haven’t been thoroughly checked. Please contact me if you see any incorrect results or have any units you would like to see added.