Conversion · km/hmph

Kilometers Per Hour to Miles Per Hour

1 kilometer / hour = 0.621371 miles per hour (mph)

Convert kilometers per hour to miles per hour instantly. 1 kilometer / hour = 0.621371 miles per hour. Free, accurate, with conversion table and formula.

Kilometer / Hour (km/h)

Mile / Hour (mph)

Unit1 km/h equals
Meter / Second (m/s)0.277778
Kilometer / Hour (km/h)1
Mile / Hour (mph)0.621371
Foot / Second (ft/s)0.911344
Knot (kn)0.539957
Mach (Ma)0.000809848

How to convert kilometers per hour to miles per hour

  1. 1Take your value in kilometers per hour (km/h).
  2. 2Multiply by 0.621371.
  3. 3The result is your value in miles per hour (mph).

Kilometers Per Hour to Miles Per Hour conversion table

Kilometers Per Hour (km/h)Miles Per Hour (mph)
10.621371
21.24274
53.10686
106.21371
2515.5343
5031.0686
10062.1371
250155.343
500310.686
1,000621.371

Frequently asked

How many miles per hour are in a kilometer / hour?

1 kilometer / hour equals 0.621371 miles per hour (mph).

How do I convert kilometers per hour to miles per hour?

Multiply the number of kilometers per hour by 0.621371 to get miles per hour.

What is 10 kilometers per hour in miles per hour?

10 km/h equals 6.214 mph.

What is 100 kilometers per hour in miles per hour?

100 km/h equals 62.14 mph.

How do I convert miles per hour back to kilometers per hour?

Multiply miles per hour by 1.60934 (the reciprocal) or use the swap button above.

Where you'll actually use this

Speed measures distance covered per unit of time. Common units include km/h, mph, m/s, knots, and the speed of light (c).

  • Driving

    Speed limits use km/h in most countries; mph in the US, UK, and a few others.

  • Aviation & maritime

    Planes and ships report speed in knots (nautical miles per hour) — 1 kn ≈ 1.852 km/h.

  • Running & cycling

    Pace apps switch between min/km and min/mi; speed in km/h vs mph depending on locale.

Common mistakes to avoid

  • kph isn't a real unit

    The correct abbreviation is km/h. 'kph' is informal and not used in technical writing.

  • Knots already includes 'per hour'

    Saying 'knots per hour' is redundant — it's just 'knots'.

Did you know?

Speed of sound varies

Mach 1 isn't a fixed speed — it depends on temperature. At sea level it's roughly 1,225 km/h, falling to ~1,062 km/h at altitude.

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