mph to km/h
Type miles per hour (mph), see kilometers per hour (km/h).
By Akash Yadav Updated 18 September 2026
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The formula
How to convert mph to km/h
To change mph into km/h, multiply by 1.609344.
km/h = mph × 1.609344
Going the other way: mph = km/h × 0.621371192237
1 mile per hour = 1.609344 km/h. This factor is the exact definition of the unit, not a rounded estimate.
Worked example
You have 60 mph. Multiply by 1.609344. 60 × 1.609344 = 96.5606 km/h.
Common values
Mph to km/h conversion table
| Mph (mph) | Km/h (km/h) |
|---|---|
| 5 mph | 8.0467 km/h |
| 10 mph | 16.0934 km/h |
| 20 mph | 32.1869 km/h |
| 25 mph | 40.2336 km/h |
| 30 mph | 48.2803 km/h |
| 35 mph | 56.327 km/h |
| 40 mph | 64.3738 km/h |
| 45 mph | 72.4205 km/h |
| 50 mph | 80.4672 km/h |
| 55 mph | 88.5139 km/h |
| 60 mph | 96.5606 km/h |
| 65 mph | 104.6074 km/h |
| 70 mph | 112.6541 km/h |
| 100 mph | 160.9344 km/h |
Before you rely on it
This factor is exact
1 mile per hour is exactly 1.609344 km/h — not a rounded approximation. It follows from the 1959 international agreement that fixed the yard at exactly 0.9144 metres, which makes the mile exactly 1609.344 metres.
The everyday shortcut, "multiply by 1.6", is about half a percent low. At 70 mph that is the difference between 112 km/h and the true 112.7 km/h — fine for conversation, not for anything that has to be right.
Speed limits are set as round numbers in local units, so a converted US limit will not match a posted European sign. 65 mph converts to about 105 km/h, and no country posts 105.
For sea and air, knots are the unit: 1 knot is one nautical mile per hour, 1.852 km/h exactly, and about 1.15 mph.
Common questions
Frequently asked questions
How many km/h is 60 mph?
60 mph is exactly 96.5606 km/h.
How many km/h is 70 mph?
70 mph, the UK motorway limit, is about 112.7 km/h.
How many km/h is 30 mph?
30 mph is about 48.3 km/h.
Is multiplying by 1.6 accurate enough?
It is about half a percent low. 100 mph is 160.9344 km/h, where the shortcut gives 160.
How fast is 1 mph in km/h?
1 mph is exactly 1.609344 km/h, by definition of the international mile.
How many km/h is 100 mph?
100 mph is exactly 160.9344 km/h.
Keep going
Related converters
- km/h to mph km/h → mph
- Miles to Kilometers mi → km
- Knots to mph kn → mph
- m/s to km/h m/s → km/h
- All speed converters
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Guides that cover this conversion
Every factor on this page is listed in our conversion methodology.