This converter app is awesome...

[Curtis Enlow]

I use it constantly. it converts just about anything you can think of, but is especially useful in rocketry and even has units of energy, etc., and it's free.

Just thought I'd pass it along.

https://play.google.com/store/apps/details?id=com.mathpad.mobile.android.wt.unit&hl=en_US

 

[manixFan]

For iOS here's what I use:

https://itunes.apple.com/us/app/globeconvert-currency-units/id334851202?mt=8

While it says currency it also does nearly every other unit you can think of, including things like pressure, acceleration, and density. You can also set favorites to quickly pull up often used conversions.

Tony

 

[caveduck]

Geek mode warning! If you are on Mac or Linux, there's the venerable 'units' command (this is cli stuff, you have been warned). It literally can do furlongs/fortnight as a velocity unit. And just about everything else. In case you somehow have some UoM it doesn't know about (unlikely after all these years!) you can add it to its definition file.

Also parses expressions so it acts as a units-aware scientific calculator. Available on Windows too if you install the Linux subsystem. It can express results as ft+in, cups+tsp, etc. Doc page here: https://www.gnu.org/software/units/. I use this thing a lot, to the point of usually leaving an iterm tab open with 'units' running.