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Kilometers per Hour to Miles per Hour

Converting Kilometers per Hour to Miles per Hour is a single multiplication when you know the factor. One km/h equals 0.62137119 mph, so multiply the value in km/h by 0.62137119. The calculator below works in both directions and accepts decimals.

Formula 1 km/h = 0.62137119 mph

Need the other direction? Miles per Hour to Kilometers per Hour.

How to convert Kilometers per Hour to Miles per Hour

Kilometres per hour is the standard road-speed unit in most of the world. Miles per hour is the standard road-speed unit in the US and UK, equal to 1.609344 km/h.

To convert Kilometers per Hour to Miles per Hour, multiply the value in km/h by 0.62137119. For example, 10 km/h × 0.62137119 = 6.213712 mph. This works because the ratio between the two units is constant for every value in speed.

Worked examples

km/hmph
1 km/h0.62137119 mph
2.5 km/h1.553428 mph
5 km/h3.106856 mph
10 km/h6.213712 mph
25 km/h15.53428 mph
50 km/h31.06856 mph
100 km/h62.137119 mph

Reverse conversion

mphkm/h
1 mph1.609344 km/h
5 mph8.04672 km/h
10 mph16.09344 km/h
25 mph40.2336 km/h
50 mph80.4672 km/h
100 mph160.9344 km/h

When this conversion is useful

This is the calculation you need when you are reading a car spec, a weather report or an aviation document from another country. Because the factor is fixed, you can use the same number for a single measurement or for a batch: 1,000 km/h is 621.371192 mph.

Is the conversion exact?

Yes for practical use: the factors come from international definitions, with rounding applied only for display.

Reference: BIPM SI Brochure and NIST SP 811. Last reviewed: 2026-11-01.

km/h to mph conversion chart

The chart lists the most requested values. For a value that is not here, use the converter at the top of the page.

Kilometers per Hour (km/h)Miles per Hour (mph)
1 km/h0.62137119 mph
2 km/h1.242742 mph
3 km/h1.864114 mph
4 km/h2.485485 mph
5 km/h3.106856 mph
6 km/h3.728227 mph
7 km/h4.349598 mph
8 km/h4.97097 mph
9 km/h5.592341 mph
10 km/h6.213712 mph
11 km/h6.835083 mph
12 km/h7.456454 mph
13 km/h8.077825 mph
14 km/h8.699197 mph
15 km/h9.320568 mph
16 km/h9.941939 mph
17 km/h10.56331 mph
18 km/h11.184681 mph
19 km/h11.806053 mph
20 km/h12.427424 mph
21 km/h13.048795 mph
22 km/h13.670166 mph
23 km/h14.291537 mph
24 km/h14.912909 mph
25 km/h15.53428 mph
26 km/h16.155651 mph
27 km/h16.777022 mph
28 km/h17.398393 mph
29 km/h18.019765 mph
30 km/h18.641136 mph
31 km/h19.262507 mph
32 km/h19.883878 mph
33 km/h20.505249 mph
34 km/h21.126621 mph
35 km/h21.747992 mph
36 km/h22.369363 mph
37 km/h22.990734 mph
38 km/h23.612105 mph
39 km/h24.233476 mph
40 km/h24.854848 mph
41 km/h25.476219 mph
42 km/h26.09759 mph
43 km/h26.718961 mph
44 km/h27.340332 mph
45 km/h27.961704 mph
46 km/h28.583075 mph
47 km/h29.204446 mph
48 km/h29.825817 mph
49 km/h30.447188 mph
50 km/h31.06856 mph
60 km/h37.282272 mph
70 km/h43.495983 mph
80 km/h49.709695 mph
90 km/h55.923407 mph
100 km/h62.137119 mph

Frequently asked questions

How many Miles per Hour are in 1 Kilometers per Hour?

1 km/h equals 0.62137119 mph.

How do I convert Kilometers per Hour to Miles per Hour?

Multiply the km/h value by 0.62137119. Example: 25 km/h = 15.53428 mph.

What is 2.5 km/h in mph?

2.5 km/h = 1.553428 mph.

Is the km/h to mph conversion exact?

Yes for practical use: the factors come from international definitions, with rounding applied only for display.

Does the calculator work offline?

Yes. The conversion runs in your browser with JavaScript, so it works after the page has loaded, even without a connection.

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