Convert kilometers per hour to miles per hour
One kilometer per hour (km/h) equals 0.621371 miles per hour (mph), so divide kilometers per hour by 1.6093 to get miles per hour.
How do you convert kilometers per hour to miles per hour?
Why does my speedometer read faster than my GPS?
Because a car speedometer is built to over-read. Under UN Regulation 39, the type-approval rule used across Europe and much of the world, the indicated speed may never be lower than the true speed and may not exceed it by more than 10 percent plus 4 km/h. A GPS measures true ground speed, so at a genuine 100 km/h (62.14 mph) the dial may legally show anything up to 114 km/h, which reads as 70.84 mph. The conversion on this page is exact to the last digit; the gap you are looking at is the instrument, not the arithmetic.
Is 100 km/h the same as 60 mph?
No, and the near miss is what makes the error stick. 100 km/h is 62.14 mph, while 60 mph is 96.56 km/h, so the two round figures sit about 3.4 km/h apart. The pairing worth memorising instead is 62 mph to 100 km/h, which is accurate to within a quarter of a kilometre per hour and lets you read a foreign dial at a glance.
kph, km/h and kmph all mean the same unit
The official symbol is km/h with a solidus, and that is what appears on signs and in legislation. kph, KPH and kmph are informal spellings that grew out of typewriters and search boxes, and none of them is a different unit. Whichever you type, the arithmetic is a division by 1.609344, the exact number of kilometres in a statute mile since the 1959 international yard and pound agreement.
km/h is not knots, and not metres per second
Three speed units get mistaken for one another in forecasts and datasheets. A knot is one nautical mile per hour, which is exactly 1.852 km/h, so a 40-knot gale is 74.08 km/h rather than 40. A metre per second is 3.6 km/h, the unit used in physics and in athletics wind readings. If a speed you read as km/h turns out to be almost twice as fast, the source was in knots; if it is out by nearly a factor of four, it was in m/s.
The limits worth converting before you drive
Cars sold in the UK and the US usually put mph on the outer ring of the dial and km/h inside it, and most of Europe reverses that, so one instrument serves both markets. Three conversions cover nearly every sign you will meet: 50 km/h is 31.07 mph, 90 km/h is 55.92 mph and 130 km/h is 80.78 mph. Going the other way, a 70 mph motorway limit is 112.65 km/h and a 25 mph US residential limit is 40.23 km/h.
Speed reference table: km/h, mph, m/s and knots
Calculated from the exact definitions: 1 mph is 1.609344 km/h, 1 knot is 1.852 km/h and 1 m/s is 3.6 km/h. Nothing here is rounded off a chart.
| Kilometres per hour | Miles per hour | Metres per second | Knots |
|---|---|---|---|
| 5 km/h | 3.11 mph | 1.39 m/s | 2.7 kn |
| 10 km/h | 6.21 mph | 2.78 m/s | 5.4 kn |
| 20 km/h | 12.43 mph | 5.56 m/s | 10.8 kn |
| 30 km/h | 18.64 mph | 8.33 m/s | 16.2 kn |
| 40 km/h | 24.85 mph | 11.11 m/s | 21.6 kn |
| 50 km/h | 31.07 mph | 13.89 m/s | 27 kn |
| 60 km/h | 37.28 mph | 16.67 m/s | 32.4 kn |
| 70 km/h | 43.5 mph | 19.44 m/s | 37.8 kn |
| 80 km/h | 49.71 mph | 22.22 m/s | 43.2 kn |
| 90 km/h | 55.92 mph | 25 m/s | 48.6 kn |
| 100 km/h | 62.14 mph | 27.78 m/s | 54 kn |
| 110 km/h | 68.35 mph | 30.56 m/s | 59.4 kn |
| 120 km/h | 74.56 mph | 33.33 m/s | 64.79 kn |
| 130 km/h | 80.78 mph | 36.11 m/s | 70.19 kn |
| 150 km/h | 93.21 mph | 41.67 m/s | 80.99 kn |
| 200 km/h | 124.27 mph | 55.56 m/s | 107.99 kn |
Sources
Kilometer per hour to mile per hour conversion table
| Kilometers per hour | Miles per hour | Miles per hour | Kilometers per hour |
|---|---|---|---|
| 1 km/h | 0.621371 mph | 1 mph | 1.6093 km/h |
| 2 km/h | 1.2427 mph | 2 mph | 3.2187 km/h |
| 3 km/h | 1.8641 mph | 3 mph | 4.828 km/h |
| 5 km/h | 3.1069 mph | 5 mph | 8.0467 km/h |
| 10 km/h | 6.2137 mph | 10 mph | 16.0934 km/h |
| 20 km/h | 12.4274 mph | 20 mph | 32.1869 km/h |
| 50 km/h | 31.0686 mph | 50 mph | 80.4672 km/h |
| 100 km/h | 62.1371 mph | 100 mph | 160.93 km/h |
| 500 km/h | 310.69 mph | 500 mph | 804.67 km/h |
| 1000 km/h | 621.37 mph | 1000 mph | 1609.34 km/h |
To convert kilometers per hour to miles per hour, divide the number of kilometers per hour by 1.6093. One kilometer per hour equals 0.621371 miles per hour, and one mile per hour equals 1.6093 kilometers per hour, so the relationship is fixed and exact. As a worked example, 10 km/h comes to 6.2137 mph. Enter your own figure in the converter above to get an instant answer, or use the swap button to flip the direction. This is a speed conversion, and like every tool on UnitGlide it runs locally in your browser with no account or upload required. The table further down shows a range of common kilometer per hour values already worked out in miles per hour, plus the reverse mile per hour to kilometer per hour direction, which is handy for quick reference or double-checking a result by hand.
Kilometer per hour to mile per hour in practice
Kilometres per hour to miles per hour is the conversion drivers reach for the moment they cross a border, and the one designed into every dual-scale speedometer.
Where it comes up
Most of the world posts speed limits in km/h, but the UK and US keep mph, so a 130 km/h motorway stretch reads as 81 mph and a 50 km/h town limit as 31 mph. Rental drivers abroad do this arithmetic at every sign, and a 30 km/h school zone becomes a gentle 19 mph. Weather forecasts flip the same way with gusts, and cyclists comparing a European GPS pace against an older mph computer meet it too.
Rounding without drifting
The exact factor is 0.621371, but 0.62 is close enough to read a dial: 120 km/h is 74.6 mph and the shortcut gives 74.4. Where the full figure earns its keep is a speeding fine abroad, where a couple of mph either side of a limit can change the penalty band, so it is worth being precise near a threshold rather than trusting a mental 0.6.
Why both scales survive
Britain went metric for weights and volumes decades ago but left its road signs in miles, which is why a UK car shows mph large and km/h small. Most of Europe did the reverse. The dual-marked dial exists precisely so a car can be driven either side of that divide without swapping the instrument, and it is the reason this conversion never quite goes away.
Frequently asked questions
How many mph is 100 km/h?
100 km/h is 62.14 mph. Divide the km/h figure by 1.609344, or multiply it by 0.621371, which is the same step.
Is 1 km/h faster than 1 mph?
No. One mph is 1.609344 km/h, so the mile per hour is the larger unit. The same speed always produces a bigger number in km/h than in mph.
Why does my GPS show a lower speed than my car's speedometer?
Type-approval rules such as UN Regulation 39 require a speedometer to read the true speed or higher, never lower, with a permitted excess of 10 percent of the true speed plus 4 km/h. GPS reports the true ground speed, so a small gap in that direction is expected rather than a fault.
How many miles per hour are in a kilometer per hour?
One kilometer per hour equals 0.621371 miles per hour. The ratio is constant, so you can multiply any number of kilometers per hour by 0.621371 to get miles per hour.
What is the formula to convert kilometers per hour to miles per hour?
Use miles per hour = kilometers per hour ÷ 1.6093. UnitGlide applies this exact formula for every value, so results stay accurate across the whole range.
How do I convert miles per hour back to kilometers per hour?
Go the other way by using one mile per hour equals 1.6093 kilometers per hour. You can also press the swap button in the converter above to flip the direction in one click.
Is this kilometer per hour to mile per hour converter accurate?
Yes. It uses internationally defined SI conversion factors, as maintained by the BIPM, and all math runs in your browser so nothing is rounded away on a server. For everyday use the displayed precision is more than enough.