To convert km/h to mph, divide by 1.609344: 120 km/h = 74.56 mph, 130 km/h = 80.78 mph and 50 km/h = 31.07 mph. For mph to km/h, multiply by 1.609344, so 100 mph = 160.9344 km/h exactly and 30 mph = 48.28 km/h. The converter handles km/h (kph, kmph), mph, knots, meters per second and feet per second in any direction, and shows the time to cover 100 km or 100 miles and the equivalent running pace.
It is for drivers renting a car abroad, travelers reading a speedometer with the "other" scale, cyclists and runners comparing app speeds, sailors and pilots working in knots, and students checking physics problems in m/s.
How to convert km/h to mph
- Take the speed in km/h, for example 120.
- Divide by 1.609344: 120 ÷ 1.609344 = 74.564543 mph.
- Round to what your speedometer shows, usually whole numbers: 75 mph.
- For mph to km/h, multiply: 75 mph × 1.609344 = 120.7008 km/h.
- For knots, use 1.852 km/h per knot; for m/s, multiply by 3.6 to get km/h.
Formula and source
mph = km/h ÷ 1.609344 and km/h = mph × 1.609344. A speed conversion uses the same factor as the distance conversion because the hour cancels out. NIST Special Publication 811 lists "mile per hour to kilometer per hour" as 1.609 344 in bold type, which NIST uses to mark exact factors, and mile per hour to meter per second as exactly 0.447 04. The exactness rests on the 1959 definition of the yard as 0.9144 m: 1,760 yards × 0.9144 m = 1,609.344 m.
A knot is one nautical mile per hour. NIST SP 811 gives the nautical mile as 1852 m and the knot as (1852/3600) m/s, so 1 knot = 1.852 km/h exactly and 1.150779 mph. One meter per second is 3.6 km/h because an hour has 3,600 seconds and a kilometer has 1,000 meters.
Most-searched speeds: km/h to mph
120 km/h to mph
120 km/h = 74.5645 mph. That is about 75 mph, so a 120 km/h sign and a 75 mph sign ask for nearly the same speed. It is also 33.33 m/s or 64.79 knots, and 100 km at this speed takes 50 minutes.
130 km/h to mph
130 km/h = 80.7783 mph. That is just under 81 mph. At this speed you cover a kilometer every 27.7 seconds. It is also 36.11 m/s or 70.19 knots, and 100 km at this speed takes 46.2 minutes.
50 km/h to mph
50 km/h = 31.0686 mph. That is about 31 mph, a little faster than a 30 mph sign. It is also 13.89 m/s or 27 knots, and 100 km at this speed takes 120 minutes.
40 km/h to mph
40 km/h = 24.8548 mph. That is just under 25 mph, close to a 25 mph sign. It is also 11.11 m/s or 21.6 knots, and 100 km at this speed takes 150 minutes.
100 km/h to mph
100 km/h = 62.1371 mph. That is about 62 mph. At 100 km/h you cover 100 km in exactly one hour, or 62.1 miles in the same hour. It is also 27.78 m/s or 54 knots, and 100 km at this speed takes 60 minutes.
340 km/h to mph
340 km/h = 211.2662 mph. That is about 211 mph, far above any ordinary road speed; a kilometer passes in about 10.6 seconds. It is also 94.44 m/s or 183.59 knots, and 100 km at this speed takes 17.6 minutes.
20 km/h to mph
20 km/h = 12.4274 mph. That is about 12.4 mph, a relaxed cycling speed, or a 3:00 /km running pace. It is also 5.56 m/s or 10.8 knots, and 100 km at this speed takes 300 minutes.
65 km/h to mph
65 km/h = 40.3891 mph. Rounded, that is 40 mph, so a 40 mph limit is a fair equivalent. It is also 18.06 m/s or 35.1 knots, and 100 km at this speed takes 92.3 minutes.
55 km/h to mph
55 km/h = 34.1754 mph. Rounded, that is 34 mph, between a 30 and a 35 mph sign. It is also 15.28 m/s or 29.7 knots, and 100 km at this speed takes 109.1 minutes.
93 km/h to mph
93 km/h = 57.7875 mph. Rounded, that is 58 mph, a little under 60 mph. It is also 25.83 m/s or 50.22 knots, and 100 km at this speed takes 64.5 minutes.
mph to km/h (miles per hour to kilometers per hour)
Going from miles per hour to km/h means multiplying, so the km/h number is always the bigger one. People search this many ways (mph to kmh, mph to km h, mh to kmh, miles h in km h, translate mph to kph) but the math is the same single step: × 1.609344.
100 mph to km/h
100 mph = 160.9344 km/h. One hundred miles per hour is exactly 160.9344 km/h because the mile is defined as 1.609344 km. That is 44.7 m/s; a mile at this speed takes 0:36 (min:s).
30 mph to km/h
30 mph = 48.2803 km/h. Thirty mph is about 48 km/h, a little under a 50 km/h sign. That is 13.41 m/s; a mile at this speed takes 2:00 (min:s).
60 mph to km/h
60 mph = 96.5606 km/h. Sixty mph is about 96.6 km/h, so a mile a minute is a little under 100 km/h. That is 26.82 m/s; a mile at this speed takes 1:00 (min:s).
Round speed-sign numbers converted
Many countries post limits in round km/h values and the US and UK in round mph values. The tables below simply convert those round numbers; they are not a list of any country's legal limits, which vary by road type and change over time. Check the local road authority for the limit that applies to you.
| km/h | mph (exact) | Nearest 5 mph |
|---|---|---|
| 30 km/h | 18.64 | 20 mph |
| 50 km/h | 31.07 | 30 mph |
| 70 km/h | 43.5 | 45 mph |
| 80 km/h | 49.71 | 50 mph |
| 90 km/h | 55.92 | 55 mph |
| 100 km/h | 62.14 | 60 mph |
| 110 km/h | 68.35 | 70 mph |
| 120 km/h | 74.56 | 75 mph |
| 130 km/h | 80.78 | 80 mph |
| mph | km/h (exact) | Nearest 10 km/h |
|---|---|---|
| 20 mph | 32.19 | 30 km/h |
| 25 mph | 40.23 | 40 km/h |
| 30 mph | 48.28 | 50 km/h |
| 35 mph | 56.33 | 60 km/h |
| 40 mph | 64.37 | 60 km/h |
| 45 mph | 72.42 | 70 km/h |
| 50 mph | 80.47 | 80 km/h |
| 55 mph | 88.51 | 90 km/h |
| 60 mph | 96.56 | 100 km/h |
| 65 mph | 104.61 | 100 km/h |
| 70 mph | 112.65 | 110 km/h |
| 75 mph | 120.7 | 120 km/h |
| 80 mph | 128.75 | 130 km/h |
| 85 mph | 136.79 | 140 km/h |
km/h to mph chart: 5 to 400 km/h
| km/h | mph | m/s | knots |
|---|---|---|---|
| 5 km/h | 3.11 | 1.39 | 2.7 |
| 10 km/h | 6.21 | 2.78 | 5.4 |
| 15 km/h | 9.32 | 4.17 | 8.1 |
| 20 km/h | 12.43 | 5.56 | 10.8 |
| 25 km/h | 15.53 | 6.94 | 13.5 |
| 30 km/h | 18.64 | 8.33 | 16.2 |
| 35 km/h | 21.75 | 9.72 | 18.9 |
| 40 km/h | 24.85 | 11.11 | 21.6 |
| 45 km/h | 27.96 | 12.5 | 24.3 |
| 50 km/h | 31.07 | 13.89 | 27 |
| 55 km/h | 34.18 | 15.28 | 29.7 |
| 60 km/h | 37.28 | 16.67 | 32.4 |
| 65 km/h | 40.39 | 18.06 | 35.1 |
| 70 km/h | 43.5 | 19.44 | 37.8 |
| 75 km/h | 46.6 | 20.83 | 40.5 |
| 80 km/h | 49.71 | 22.22 | 43.2 |
| 85 km/h | 52.82 | 23.61 | 45.9 |
| 90 km/h | 55.92 | 25 | 48.6 |
| 93 km/h | 57.79 | 25.83 | 50.22 |
| 95 km/h | 59.03 | 26.39 | 51.3 |
| 100 km/h | 62.14 | 27.78 | 54 |
| 105 km/h | 65.24 | 29.17 | 56.7 |
| 110 km/h | 68.35 | 30.56 | 59.4 |
| 115 km/h | 71.46 | 31.94 | 62.1 |
| 120 km/h | 74.56 | 33.33 | 64.79 |
| 125 km/h | 77.67 | 34.72 | 67.49 |
| 130 km/h | 80.78 | 36.11 | 70.19 |
| 135 km/h | 83.89 | 37.5 | 72.89 |
| 140 km/h | 86.99 | 38.89 | 75.59 |
| 145 km/h | 90.1 | 40.28 | 78.29 |
| 150 km/h | 93.21 | 41.67 | 80.99 |
| 160 km/h | 99.42 | 44.44 | 86.39 |
| 170 km/h | 105.63 | 47.22 | 91.79 |
| 180 km/h | 111.85 | 50 | 97.19 |
| 190 km/h | 118.06 | 52.78 | 102.59 |
| 200 km/h | 124.27 | 55.56 | 107.99 |
| 210 km/h | 130.49 | 58.33 | 113.39 |
| 220 km/h | 136.7 | 61.11 | 118.79 |
| 230 km/h | 142.92 | 63.89 | 124.19 |
| 240 km/h | 149.13 | 66.67 | 129.59 |
| 250 km/h | 155.34 | 69.44 | 134.99 |
| 260 km/h | 161.56 | 72.22 | 140.39 |
| 270 km/h | 167.77 | 75 | 145.79 |
| 280 km/h | 173.98 | 77.78 | 151.19 |
| 290 km/h | 180.2 | 80.56 | 156.59 |
| 300 km/h | 186.41 | 83.33 | 161.99 |
| 320 km/h | 198.84 | 88.89 | 172.79 |
| 340 km/h | 211.27 | 94.44 | 183.59 |
| 350 km/h | 217.48 | 97.22 | 188.98 |
| 400 km/h | 248.55 | 111.11 | 215.98 |
mph to km/h chart: 5 to 300 mph
| mph | km/h | m/s | ft/s |
|---|---|---|---|
| 5 mph | 8.05 | 2.24 | 7.33 |
| 10 mph | 16.09 | 4.47 | 14.67 |
| 15 mph | 24.14 | 6.71 | 22 |
| 20 mph | 32.19 | 8.94 | 29.33 |
| 25 mph | 40.23 | 11.18 | 36.67 |
| 30 mph | 48.28 | 13.41 | 44 |
| 35 mph | 56.33 | 15.65 | 51.33 |
| 40 mph | 64.37 | 17.88 | 58.67 |
| 45 mph | 72.42 | 20.12 | 66 |
| 50 mph | 80.47 | 22.35 | 73.33 |
| 55 mph | 88.51 | 24.59 | 80.67 |
| 60 mph | 96.56 | 26.82 | 88 |
| 65 mph | 104.61 | 29.06 | 95.33 |
| 70 mph | 112.65 | 31.29 | 102.67 |
| 75 mph | 120.7 | 33.53 | 110 |
| 80 mph | 128.75 | 35.76 | 117.33 |
| 85 mph | 136.79 | 38 | 124.67 |
| 90 mph | 144.84 | 40.23 | 132 |
| 95 mph | 152.89 | 42.47 | 139.33 |
| 100 mph | 160.93 | 44.7 | 146.67 |
| 110 mph | 177.03 | 49.17 | 161.33 |
| 120 mph | 193.12 | 53.64 | 176 |
| 130 mph | 209.21 | 58.12 | 190.67 |
| 140 mph | 225.31 | 62.59 | 205.33 |
| 150 mph | 241.4 | 67.06 | 220 |
| 160 mph | 257.5 | 71.53 | 234.67 |
| 180 mph | 289.68 | 80.47 | 264 |
| 200 mph | 321.87 | 89.41 | 293.33 |
| 250 mph | 402.34 | 111.76 | 366.67 |
| 300 mph | 482.8 | 134.11 | 440 |
Knots to km/h and mph
| Knots | km/h | mph | m/s |
|---|---|---|---|
| 1 kn | 1.852 | 1.15 | 0.51 |
| 5 kn | 9.26 | 5.75 | 2.57 |
| 10 kn | 18.52 | 11.51 | 5.14 |
| 15 kn | 27.78 | 17.26 | 7.72 |
| 20 kn | 37.04 | 23.02 | 10.29 |
| 25 kn | 46.3 | 28.77 | 12.86 |
| 30 kn | 55.56 | 34.52 | 15.43 |
| 40 kn | 74.08 | 46.03 | 20.58 |
| 50 kn | 92.6 | 57.54 | 25.72 |
| 100 kn | 185.2 | 115.08 | 51.44 |
| 250 kn | 463 | 287.69 | 128.61 |
| 500 kn | 926 | 575.39 | 257.22 |
Worked examples
Renting a car with a km/h speedometer
You are used to cruising at 70 mph. 70 × 1.609344 = 112.7 km/h, so hold about 113 km/h on the dial. If the posted number is 110, that is 68.4 mph.
Running treadmill speed to pace
A treadmill reads 12 km/h. In mph: 12 ÷ 1.609344 = 7.46 mph. Pace: 3,600 ÷ 12 = 300 s, so 5:00 per km, or 8:03 per mile. For full pace and race-time tables see the km to miles converter.
Wind speed in m/s
A forecast gives gusts of 15 m/s. × 3.6 = 54 km/h, ÷ 1.609344 = 33.6 mph, ÷ 1.852 (in km/h) = 29.2 knots.
Common mistakes
- Going the wrong direction. mph values are always smaller than the same speed in km/h. If 120 km/h turns into 193, you multiplied instead of dividing.
- Mixing knots and mph. A knot is 1.151 mph, so a 30-knot boat is doing 34.5 mph, not 30.
- Using 1.6 for high speeds. 300 km/h ÷ 1.6 = 187.5 mph, but the exact answer is 186.4 mph. Use 1.609344 when the number matters.
- Forgetting 3.6 for m/s. m/s to km/h is × 3.6, not × 1,000. Dividing by 1,000 alone gives km per second.
- Reading a dual speedometer's inner ring as the main unit. On many cars the smaller inner numbers are the secondary unit; check which ring matches the posted signs.
Related: kilometers to miles for distances, fuel economy (mpg ↔ L/100 km) and meters to feet.
Frequently asked questions
How do you convert km/h to mph?
Divide km/h by 1.609344. For example, 120 km/h ÷ 1.609344 = 74.5645 mph. Multiplying by 0.621371 gives the same answer to six digits.
What is 120 km/h in mph?
120 km/h = 74.5645 mph, which rounds to 75 mph. In the reverse direction, 120 mph is 193.12 km/h.
What is 130 km/h in mph?
130 km/h is 80.778 mph, about 81 mph.
How fast is 50 km/h in mph?
50 km/h is 31.069 mph, about 31 mph. 40 km/h is 24.85 mph and 20 km/h is 12.43 mph.
What is 100 mph in km/h?
100 mph = exactly 160.9344 km/h. 100 km/h, going the other way, is 62.137 mph.
How do you convert mph to km/h?
Multiply mph by 1.609344. 30 mph × 1.609344 = 48.28 km/h and 60 mph = 96.561 km/h.
Is kph the same as km/h?
Yes. kph, kmph, km/hr and km/h all mean kilometers per hour. km/h is the SI-style symbol; the others are informal spellings. Likewise mph, mi/h and miles/h all mean miles per hour.
How many mph is 1 knot?
One knot is one nautical mile per hour, 1,852 m per hour, which is 1.1508 mph and exactly 1.852 km/h.
How do I convert m/s to km/h and mph?
Multiply m/s by 3.6 for km/h. For mph divide m/s by 0.44704: 10 m/s = 36 km/h = 22.369 mph.
What is a quick mental conversion from km/h to mph?
Halve the km/h and add a tenth of the original: 120 → 60 + 12 = 72, against an exact 74.6. For a closer answer multiply by 5 and divide by 8: 120 × 5 ÷ 8 = 75, only 0.6% high.
How long does 100 km take at 120 km/h?
50 minutes. At 130 km/h it takes 46.2 minutes, so the extra 10 km/h saves about 3.8 minutes per 100 km.
Sources & method
- NIST SP 811, Appendix B.8 — mile per hour to km/h = 1.609 344 and to m/s = 0.447 04 (bold = exact); knot = 0.514 444 m/s
- NIST SP 811, Chapter 5, Table 9 — 1 nautical mile = 1852 m; 1 knot = 1 nautical mile per hour = (1852/3600) m/s
- NIST Handbook 44 (2026), Appendix C — 1 mile = 1.609 344 km (exactly); 1 international nautical mile = 1 852 m (exactly)
- Federal Register Notice 59-5442 (1959) — 1 yard = 0.9144 m exactly, the basis of the international mile
Results are estimates for general information. Found an error? It helps everyone — see our methodology.