I am Canadian and have done that for 50 years; I was 30 when Canada "converted."

Here's for km and miles.

km in miles you multiply by 0.6

miles to km you multiply by 1.6

100 km/h X 0.6 = 60 m/h (vs 62 m/h)

60 m/h X 1.6 = 60 + 36 = 96 (vs 96.5 km/h)

I guess everybody knows that? It is so simple!

First time I mention this in 50 years.