Speed
Miles per hour to kilometres per hour
One multiplication, no time factor. The hour cancels because both rates are per hour, so only the distance unit changes.
The Formula
kph = mph x 1.609344
One multiplication, no time factor. The hour cancels because both rates are per hour, so only the distance unit changes.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| mph | Speed in miles per hour | miles per hour | The road-speed unit used on signs in the United States and the United Kingdom. |
| 1.609344 | Kilometres per mile | km per mi | Exact, from 1609.344 metres to the statute mile under the 1959 agreement. |
| kph | Speed in kilometres per hour | kilometres per hour | 60 mph becomes 96.56064 kph by this single multiplication. |
What Each Symbol Means
mphmiles per hour
Speed in miles per hour
The road-speed unit used on signs in the United States and the United Kingdom.
1.609344km per mi
Kilometres per mile
Exact, from 1609.344 metres to the statute mile under the 1959 agreement.
kphkilometres per hour
Speed in kilometres per hour
60 mph becomes 96.56064 kph by this single multiplication.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to convert mph to kph page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Convert Mph To Kph, filed under Unit Conversion. Every number the guide produces comes from substituting into this one line.