The SI base unit for this calculator is metres per second, m/s.
Typically to convert from UOM1 to UOM2 you perform the following key sequence:
Enter the UOM1 value
Tap
Tap the UOM of the value.
Now to convert the value:
Tap
Tap the UOM of UOM2
The video yds to m shows an example of using the length conversion calculator which is typical for all calculators.
Anytime you are unsure of the abbreviations on the labels, use the long press gesture to display the hint for that key.
Following the steps in General Key Details will allow you to see the conversion factors used in the calculations.
Conversion of units - Wikipedia, the free encyclopedia