Windows 10 comes with a free app that makes length conversions easy. It’s the calculator app. The Windows Calculator does a whole lot more than just adding and subtracting. It can do your metric conversions, date calculation, and much more.
Check out how to do easy volume conversion with Windows Calculator: https://community.windows.com/en-us/videos/windows-101-volume-conversions-using-the-calculator-app/rqCJJD054gg