Miles per hour to Kilometers per hour Converter

Speed conversion · Updated 2026-10-04

Converting miles per hour to kilometers per hour is a multiplication by a fixed factor: 1 mph = 1.609344 km/h. The table below covers the values people look up most often, and the formula section shows exactly where that factor comes from.

Because one mile per hour works out to 1.609344 km/h, the kilometer per hour is the larger unit of the two: a figure given in kilometer per hour always carries a larger number than the same measurement in mile per hour. A chart drawn in mph can hide that, so check which label the axis uses before you compare two readings.

In engineering, kinematic figures quoted in miles per hour often have to be restated in kilometers per hour before they can be compared with a manufacturer curve.

The conversion factor used here is 1.609344 km/h per mile per hour (6 significant digits as shown). Kept to seven figures it covers professional measurement; if you round it to two or three decimals for a spreadsheet, the error scales with the input — at a value of 1,000 mph a factor rounded to three decimals can be off by a measurable amount. The reverse direction uses 0.6213712 mph per km/h, the exact reciprocal, so a round trip through both pages returns your original number.

Miles per hour to Kilometers per hour formula

Use this formula to convert any mile per hour value to kilometers per hour:

Worked example: 100 mph × 1.609344 = 160.9344 km/h.

Miles per hour to Kilometers per hour conversion table

Miles per hour (mph)	Kilometers per hour (km/h)
0.5 mph	0.804672 km/h
1 mph	1.609344 km/h
2 mph	3.218688 km/h
5 mph	8.04672 km/h
10 mph	16.09344 km/h
20 mph	32.18688 km/h
50 mph	80.4672 km/h
100 mph	160.9344 km/h
500 mph	804.672 km/h
1000 mph	1609.344 km/h

How to convert miles per hour to kilometers per hour

Multiply the mile per hour value by 1.609344 to get the equivalent in kilometers per hour. This single factor works for every value in the table above and for anything else you need — there is no per-value adjustment, which is why a conversion table and a calculator always agree.

If you need the opposite direction, use the Kilometers per hour to Miles per hour converter instead of dividing by hand; both pages use the same source factors. For every other mph conversion in one place, see the mph conversion hub.

Frequently asked questions

How many kilometers per hour are in 1 mile per hour?
1 mile per hour = 1.609344 km/h.

What is 100 miles per hour in kilometers per hour?
100 mph = 160.9344 km/h.

Is converting miles per hour to kilometers per hour the same as kilometers per hour to miles per hour?
No — the direction changes the multiplier. The reverse conversion (1 km/h = 0.6213712 mph) is on the Kilometers per hour to Miles per hour page.

Related conversions

Try the ConvBolt Unit Converter for any other speed unit, browse the Speed conversions, or read our conversion guides.