kph x 0.621 = mph.
http://wiki.answers.com/Q/What_is_the_formula_for_...

1. Multiply the speed in mph by 1.609344 km per mile. For example, 55 mph is 88.51392 kph. For most practical intents, multiplying by 1.6 is accurate enough. 2. Convert from kph to
http://www.ehow.com/how_2306811_convertmphkph.ht...

1 Determine the speed in mph (miles per hour) you want to convert to kph (kilometers per hour).
http://www.wikihow.com/ConvertMphtoKph

Mph X 1.609344 = Kph. Kph / 1.609344 = Mph.
http://answers.yahoo.com/question/index?qid=200606...
