Miles per Hour to Kilometers per Hour Converter (mph to km/h)
1 mph = 1.609344 km/h exactly. Convert miles per hour to km/h for UK and US speed limits, car specs and storm winds, with mph and km/h charts.
Kilometer per Hour (km/h) = Mile per Hour (mph) × 1.609344
Mile per Hour (mph): Miles per hour is the road-speed unit used in the United States and the United Kingdom. The international mile is exactly 1609.344 m, so 1 mph is exactly 0.44704 m/s or 1.609344 km/h.
Kilometer per Hour (km/h): The kilometre per hour is the speed unit on road signs and speedometers in most of the world. Because 1 km is 1000 m and 1 hour is 3600 s, 1 km/h is exactly 5/18 m/s (about 0.2778 m/s).
| Mile per Hour (mph) | Kilometer per Hour (km/h) |
|---|---|
| 1 | 1.609344 |
| 5 | 8.04672 |
| 10 | 16.09344 |
| 25 | 40.2336 |
| 50 | 80.4672 |
| 100 | 160.9344 |
The United Kingdom and the United States post speed limits in miles per hour, as do several of their territories and a few smaller countries, while almost everywhere else uses kilometers per hour. Drivers renting a car abroad, readers comparing car reviews and anyone checking a storm report in mph meet this conversion. Since the international mile is exactly 1.609344 km, 1 mph is exactly 1.609344 km/h.
Many speedometers in both countries carry a small km/h scale, but road signs, fines and driving tests use mph only. Miles per hour and km/h convert with the same factor as miles and kilometers: a 70 mph motorway limit comes to about 113 km/h, a little below the 120 to 130 km/h motorway limits common in continental Europe.
How to use this tool
- Type a value in the Mile per Hour box to see it in kilometers per hour, or type in the Kilometer per Hour box to convert the other way.
- Press ⇄ to swap the two units, or Load example for a typical value.
- Check the charts below for common values; for other units, open the Speed converter.
Formula
Kilometer per Hour (km/h) = Mile per Hour (mph) × 1.609344
Mile per Hour (mph) = Kilometer per Hour (km/h) × 0.621371192237
Both factors come from exact definitions: 1 kilometer per hour = 0.621371192237 miles per hour and 1 mile per hour = 1.609344 kilometers per hour (shown to 12 significant digits).
Example
Two conversions worked with the same factors the converter uses:
70 mph × 1.609344 = 112.65408 km/h
100 km/h × 0.621371192237 ≈ 62.1371 mph
Mile per Hour to Kilometer per Hour chart
Common values from miles per hour to kilometers per hour, rounded to four decimal places.
| Mile per Hour (mph) | Kilometer per Hour (km/h) |
|---|---|
| 5 | 8.0467 |
| 10 | 16.0934 |
| 15 | 24.1402 |
| 20 | 32.1869 |
| 25 | 40.2336 |
| 30 | 48.2803 |
| 35 | 56.327 |
| 40 | 64.3738 |
| 45 | 72.4205 |
| 50 | 80.4672 |
| 55 | 88.5139 |
| 60 | 96.5606 |
| 65 | 104.6074 |
| 70 | 112.6541 |
| 75 | 120.7008 |
| 80 | 128.7475 |
| 85 | 136.7942 |
| 90 | 144.841 |
| 100 | 160.9344 |
| 120 | 193.1213 |
| 150 | 241.4016 |
| 200 | 321.8688 |
Kilometer per Hour to Mile per Hour chart
The reverse direction for values people often look up.
| Kilometer per Hour (km/h) | Mile per Hour (mph) |
|---|---|
| 10 | 6.2137 |
| 20 | 12.4274 |
| 30 | 18.6411 |
| 40 | 24.8548 |
| 50 | 31.0686 |
| 60 | 37.2823 |
| 70 | 43.496 |
| 80 | 49.7097 |
| 90 | 55.9234 |
| 100 | 62.1371 |
| 110 | 68.3508 |
| 120 | 74.5645 |
| 130 | 80.7783 |
Speed limits posted in miles per hour
| Road | Mile per Hour (mph) | Kilometer per Hour (km/h) |
|---|---|---|
| Built-up areas in Wales (default since 2023) | 20 | 32.1869 |
| Built-up areas in England, Scotland and N. Ireland | 30 | 48.2803 |
| UK single carriageway, national limit for cars | 60 | 96.5606 |
| UK motorway and dual carriageway limit for cars | 70 | 112.6541 |
| US national speed limit set in 1974 | 55 | 88.5139 |
| Texas State Highway 130, highest posted in the US | 85 | 136.7942 |
Quick mental estimate
Add 60% to the mph figure: 50 mph → 50 + 30 = 80 km/h, against an exact 80.47 km/h. The shortcut multiplies by 1.6, about 0.6% under the true factor, so at road speeds it stays within 1 km/h of the exact answer.
Use the converter or the charts when the exact figure matters.
The two units
Mile per Hour (mph): Miles per hour is the road-speed unit used in the United States and the United Kingdom. The international mile is exactly 1609.344 m, so 1 mph is exactly 0.44704 m/s or 1.609344 km/h.
Kilometer per Hour (km/h): The kilometre per hour is the speed unit on road signs and speedometers in most of the world. Because 1 km is 1000 m and 1 hour is 3600 s, 1 km/h is exactly 5/18 m/s (about 0.2778 m/s).
Frequently asked questions
Is 70 mph faster than 110 km/h?
Yes. 70 mph is about 112.7 km/h, a little faster than a 110 km/h limit and a little slower than 120 km/h.
Why does the UK still use mph when it is otherwise metric?
Road signs were left out of the UK's move to metric units, and the national limits are set in miles per hour by law. Distances on UK road signs are given in miles and yards as well.
How does a 0–60 mph time compare with 0–100 km/h?
60 mph is about 96.6 km/h, so a 0–100 km/h time is slightly longer, usually by a few tenths of a second. Carmakers measure the two separately, so one cannot be converted exactly into the other.
How precise is the result?
The converter uses the exact definitions above with browser floating-point arithmetic and shows up to 12 significant digits. The charts round to four decimal places for reading.
Sources
Last updated:
Page address with these inputs: https://kakao.mobile/tools/miles-per-hour-to-kilometers-per-hour-converter/
Cite or embed this tool
kakaoCalc. (2026, November 8). Miles per Hour to Kilometers per Hour Converter (mph to km/h). https://kakao.mobile/tools/miles-per-hour-to-kilometers-per-hour-converter/
“Miles per Hour to Kilometers per Hour Converter (mph to km/h).” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/miles-per-hour-to-kilometers-per-hour-converter/.
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