Written by Muneeb Rana · Last updated 26 October 2026
Quick answer: To convert mph to kmh, multiply miles per hour by 1.609344. So 30 mph is 48.3 km/h, 60 mph is 96.6 km/h and 70 mph is 112.7 km/h. Enter any speed in the converter for an instant answer, or use the table below, which covers everything from walking pace to motorway speeds.
TL;DR
- km/h = mph × 1.609344.
- Shortcut: multiply by 1.6.
- 60 mph ≈ 97 km/h.
- UK 70 mph motorway limit ≈ 113 km/h.
- Table below.
MPH to KMH formula
km/h = mph × 1.609344. The factor is exact because the international mile is defined as 1,609.344 metres. Multiplying by 1.6 gets within half a percent, which is plenty for reading a sign.
Mental method
Add half, then add a tenth of the original: 50 mph → 50 + 25 + 5 = 80 km/h (exact: 80.5). For 70: 70 + 35 + 7 = 112 (exact: 112.7).
Conversion table
| mph | km/h |
|---|---|
| 5 | 8.0 |
| 10 | 16.1 |
| 20 | 32.2 |
| 30 | 48.3 |
| 40 | 64.4 |
| 50 | 80.5 |
| 60 | 96.6 |
| 70 | 112.7 |
| 80 | 128.7 |
| 90 | 144.8 |
| 100 | 160.9 |
| 110 | 177.0 |
| 120 | 193.1 |
| 130 | 209.2 |
| 140 | 225.3 |
| 150 | 241.4 |
US and UK limits in km/h
UK national limits: 30 mph in built-up areas (48 km/h), 60 mph on single carriageways (97 km/h), 70 mph on motorways (113 km/h). US state limits vary widely, with many interstates at 65–75 mph (105–121 km/h) and a few rural segments higher. See US speed limits.
Common speeds
20 mph ≈ 32 km/h; 30 ≈ 48; 40 ≈ 64; 50 ≈ 80; 60 ≈ 97; 70 ≈ 113; 80 ≈ 129.
Why the factor is exact
Since 1959 the international mile has been exactly 1,609.344 m, so 1 mph equals exactly 1.609344 km/h.
Or just switch units
Driving a US car in Canada? Set Speedometer PRO to KM/H and read the signs directly.
Related: Free speed tools · MPH guide: speed units explained · KMH to MPH converter · MPH vs km/h · US speed limits explained · Speedometer MPH and KM/H units · Knots to MPH converter · MPH to meters per second converter
Get Speedometer PRO on Google Play · Download on the App Store · Set it up before you move; never handle your phone while driving.
Sources
- Unit conversion (NIST Office of Weights and Measures): nist.gov (accessed 26 October 2026)
- Miles per hour (Wikipedia): en.wikipedia.org (accessed 26 October 2026)
- Kilometres per hour (Wikipedia): en.wikipedia.org (accessed 26 October 2026)
- Mile (Wikipedia): en.wikipedia.org (accessed 26 October 2026)
FAQ
How do I convert mph to km/h?
Multiply by 1.609344. For a quick estimate, multiply by 1.6; the result will be within about half a percent.
What is 60 mph in km/h?
96.56 km/h. Many people round it to 97, or to 100 when comparing car acceleration figures loosely.
What is 70 mph in km/h?
112.65 km/h. That is the UK motorway limit expressed in metric units.
What is 30 mph in km/h?
48.28 km/h. It is close to, but not the same as, the 50 km/h urban limit common in Europe.
Is the factor exact?
Yes. Because the mile is defined as exactly 1,609.344 metres, 1.609344 is an exact conversion factor, not an approximation.