Wrenchbench is the ultimate all-in-one conversion tool. Weighing in at just a few megabytes, it's a portable, accurate, and user-friendly bit of freeware. Unlike common programs, Wrenchbench is free forever. No ads, no "trial", just free. And since it doesn't require installation of any registration of sorts, you can have it up and running in just a few minutes.
Currently, the program is in it's beta state, with only a few conversion options available. But, before the full version is released the program will see a massive slew of updates to the conversion engine and the UI.
Wrenchbench is unlike all other unit converters. For starters, it's completely free. No ads, no pop-ups, no trials. Secondly, it doesn't have any bloatware attached to it, like toolbars and and third-party offers. Thirdly, it's ultraportable and a standalone, so it can be executed on ANY operating system from anywhere anytime, so long as you have Java. And lastly, it is extremely accurate, with conversion rates being accurate up to 9 decimal places.