There is an imperial switch on the map, so you can see the ground speed in mph. Wind speed in knots is fairly standard, so that doesn't need translating, and kph will be well known to anyone who travels outside the UK. Since the ETA is also shown I doubt that much maths goes on, but I do sometimes calculate it in my head to see what extra time is allowed for the landing process. But that's usually in the 10 to 15 minute range so it's not really worth doing.