To convert kph to mph, divide by 1.609344 or multiply by about 0.621371, because one mile is exactly 1.609344 km. Formula: mph = km/h / 1.609344. For example, 100 km/h ≈ 62.14 mph and 50 km/h ≈ 31.07 mph.
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How to use the kph to mph converter
- Enter the speed in kilometers per hour, for example 80.
- Read the kph to mph converter result: 80 ÷ 1.609344 ≈ 49.71 mph.
- For a rough check, multiply by 5 and divide by 8: 80 × 5 ÷ 8 = 50 mph.
What is the KPH to MPH formula?
miles per hour = kilometers per hour ÷ 1.609344 (≈ × 0.621371)
The reverse is kilometers per hour = miles per hour × 1.609344.
Because the mile is exactly 1.609344 km, 1 mph is exactly 1.609344 km/h. The multiplier 0.621371 is rounded to six significant digits; the kph to mph calculator uses the full-precision value.
What are kilometers per hour and miles per hour?
Speed is distance travelled per unit time. The SI unit is the meter per second. Road signs use km/h or mph (1 mph = 1.609344 km/h exactly), and ships and aircraft use knots (1 knot = 1.852 km/h).
- Kilometer per hour (km/h): 1 km/h = 0.2777777778 m/s (Metric unit).
- Mile per hour (mph): 1 mph = 0.44704 m/s (US/Imperial unit).
Kph to mph worked examples
- A 100 km/h limit: 100 ÷ 1.609344 = 62.1371 mph
- A 50 km/h town limit: 50 ÷ 1.609344 = 31.0686 mph
- A 130 km/h motorway limit: 130 ÷ 1.609344 = 80.7783 mph
Conversion chart
| km/h | mph | km/h | mph |
|---|---|---|---|
| 10 | 6.2137 | 90 | 55.9234 |
| 20 | 12.4274 | 100 | 62.1371 |
| 30 | 18.6411 | 110 | 68.3508 |
| 40 | 24.8548 | 120 | 74.5645 |
| 50 | 31.0686 | 130 | 80.7783 |
| 60 | 37.2823 | 150 | 93.2057 |
| 70 | 43.496 | 200 | 124.27 |
| 80 | 49.7097 | 300 | 186.41 |
Values are rounded to four decimal places, or two for results of 100 or more.
Quick mental conversion
Multiply by 0.6 for a quick estimate (it understates by about 3.5%): 100 km/h ≈ 60 mph (exact 62.1).
Kilometers per hour from miles per hour: reverse chart
Going the other way, kilometers per hour = miles per hour × 1.609344. Common values:
| miles per hour | kilometers per hour |
|---|---|
| 1 | 1.609344 |
| 2 | 3.218688 |
| 5 | 8.04672 |
| 10 | 16.09344 |
| 20 | 32.18688 |
| 50 | 80.4672 |
| 100 | 160.9344 |
| 500 | 804.672 |
| 1,000 | 1,609.344 |
Common speed limits in mph
Road signs in most countries show km/h. Typical limits converted to mph:
| km/h | mph |
|---|---|
| 30 | 18.64 |
| 50 | 31.07 |
| 60 | 37.28 |
| 80 | 49.71 |
| 90 | 55.92 |
| 100 | 62.14 |
| 110 | 68.35 |
| 120 | 74.56 |
| 130 | 80.78 |
Check local rules: limits vary by country, road type and weather.
Speedometers, wind speed and sport
Cars sold in the UK and US show mph as the main scale, with km/h on an inner scale; most other markets reverse this. Weather services quote wind in km/h, mph, m/s or knots, and tennis serve speeds appear in both: a 200 km/h serve is about 124.3 mph. Aircraft and ships use knots instead, where 1 knot is exactly 1.852 km/h. Use the mph to kph converter for the reverse and the speed converter for knots and m/s.
Motorways and e-bikes
Many European motorways have a limit of 130 km/h, which is about 81 mph. Rental cars there show km/h on the main dial, so drivers used to mph should set the cruise control by the km/h reading rather than trying to convert while driving. A kph to mph conversion before the trip helps you know what the signs mean.
E-bikes are another example. In the EU, pedal assistance on a standard e-bike must stop at 25 km/h, which is about 15.5 mph. In the US, class 1 and 2 e-bikes are limited to 20 mph, or about 32 km/h. Bikes imported from one market to the other may need their settings changed.
The exact factor is 0.621371. Multiplying by 0.6 and adding a little is close enough for road signs.
Speedometers in cars sold in Canada and the UK show both scales, with the main one matching local signs. If you buy an imported car, the secondary scale may be small or missing, so learn a few anchors: 50 km/h is about 31 mph, 80 km/h about 50 mph, and 100 km/h about 62 mph.
Related converters and calculators
Related conversions:
- Mph to kph: mph to km/h
- Miles to km: distance
- Speed calculator: distance and time
- Speed converter: km/h and mph
Sources
NIST Special Publication 811, Appendix B; NIST: SI units – length.
Questions about this calculator
How do I convert kph to mph?
Divide by 1.609344, or multiply by 0.621371. 100 km/h ≈ 62.14 mph.
What is 120 km/h in mph?
About 74.56 mph.
Is kph the same as km/h?
Yes. km/h is the SI-style symbol; kph is an informal abbreviation.
What is a quick way to estimate kph to mph?
Multiply by 5 and divide by 8, or take 60% and add a little.
How many mph is 1 km/h?
About 0.621371 mph.
Check the assumptions and units before relying on a result. Financial, tax and health estimates do not replace advice for your individual circumstances.
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