Convert kph to mph

1. How to convert kph to mph

The conversion is a single multiplication: mph = km/h × 0.621371192237. Both units are defined against the same base — the metre per second (m/s) — so the factor is fixed and the result is exact to the precision shown.

Worked at the two values people ask for most: 1 km/h = 0.62137119 mph and 60 km/h = 37.282272 mph. Going the other way, km/h = mph × 1.609344, so 1 mph = 1.609344 km/h — a direction with its own page, mph to kph.

Results are given to eight significant figures. That is more precision than most jobs need — for a rough figure, treat 1 km/h as about 0.62137119 mph and adjust — but rounding early and multiplying afterwards is how a small error becomes a visible one, so the full figure is what the converter carries.

2. Kilometres per hour to Miles per hour conversion table

Every row is the same factor applied — nothing in the table is a special case, and any value in between behaves the same way. Type your own figure into the converter above and the Formula tile shows the arithmetic being used, so the result is checkable rather than taken on trust.

3. What the two units are

• Kilometres per hour (km/h). One km/h is 0.27777778 m/s.
• Miles per hour (mph). One mph is 0.44704 m/s.

Both are converted through the metre per second (m/s): the value is multiplied by its own unit's factor to reach the base, then divided by the target unit's factor to leave it. No direct kph to mph factor has to exist or be kept correct, which is also why the converter can show the same value in all 5 speed units at once.

Speed converts through metres per second. A knot is one nautical mile per hour, which makes it exactly 1.852 km/h — the reason aviation and shipping still use it is that one knot for one hour is one minute of latitude, so it maps onto a chart without arithmetic.

If the pair you actually want is not this one, the full unit converter runs every 5 speed units off the same factor table, along with 11 other categories of measurement.