km/h vs kph

km/h and kph both are nouns.

Word	Noun	Adjective	Verb	Adverb
km/h	Yes	No	No	No
kph	Yes	No	No	No

As nouns, km/h and kph are synonyms defined as:

km/h and kph: the ratio of the distance traveled (in kilometers) to the time spent traveling (in hours)

Other synonyms of km/h include kilometers per hour, kilometres per hour.

km/h (noun)	kph (noun)
the ratio of the distance traveled (in kilometers) to the time spent traveling (in hours)	the ratio of the distance traveled (in kilometers) to the time spent traveling (in hours)