US and UK roads post speed limits in miles per hour; almost everywhere else uses kilometers per hour. That matters when you rent a car abroad with a km/h speedometer, read international car reviews, compare a treadmill in mph with a training plan in minutes per kilometer, or follow sports reported in metric. This converter gives the exact km/h figure, plus meters per second and the time it takes to cover a kilometer at that speed.
How to use the mph to km/h converter
- Enter the speed in Miles per hour (mph).
- Read the result in km/h, with meters per second and the Time per kilometer at that speed.
- The chart lists 1 to 200 mph, which covers walking, running, cycling, driving and racing speeds.
MPH to km/h formula
The factor is exact, since an hour is an hour on both sides and one mile is exactly 1.609344 km. For SI speed:
Worked example: a 65 mph highway
Step 1. 65 × 1.609344 = 104.607 km/h.
Step 2. In meters per second: 65 × 0.44704 = 29.058 m/s.
Step 3. At that speed one kilometer goes by every 60 ÷ 104.607 = 0.574 minutes, about 34 seconds.
Example: a treadmill set to 6 mph
A runner’s treadmill reads 6 mph, but their training plan gives paces per kilometer.
Step 1. 6 × 1.609344 = 9.656 km/h.
Step 2. 60 ÷ 9.656 = 6.214 minutes per kilometer, which is 6:13 per km (and 10:00 per mile).
The running pace calculator goes further, with finish-time predictions and splits.
US speed limits in km/h
| Typical setting | mph | km/h |
|---|---|---|
| Residential street | 25 | 40.23 |
| Urban arterial | 35 | 56.33 |
| Suburban highway | 45 | 72.42 |
| Rural two-lane road | 55 | 88.51 |
| Interstate (many states) | 65 | 104.61 |
| Interstate / UK motorway limit | 70 | 112.65 |
| Rural interstate (western states) | 75 | 120.70 |
| Highest rural limits | 80 | 128.75 |
| Highest posted US limit (a Texas toll road) | 85 | 136.79 |
Most analog speedometers in US-market cars show both scales, usually with km/h on the smaller inner ring.
Mental shortcuts
- ×1.6: simple and about 0.6% low. 50 mph → 80 km/h (exact 80.47).
- Add 60%: 30 mph + 18 = 48 km/h (exact 48.28).
- The 5-8 rule: 5 mph ≈ 8 km/h, so 25 ≈ 40, 50 ≈ 80, 75 ≈ 120.
Sports and weather
Baseball pitch speeds, tennis serves and hurricane wind speeds in US media are given in mph. Converting helps when comparing with international coverage: a 100 mph fastball is 160.9 km/h, and a hurricane’s minimum Category 1 wind of 74 mph is 119 km/h. For wind in knots or m/s, the speed converter covers every unit. For the opposite direction, use km/h to mph.
Frequently asked questions
How many km/h is 1 mph?
Exactly 1.609344 km/h, because one mile is exactly 1.609344 km.
What is 60 mph in km/h?
60 mph is 96.56 km/h. A car doing 60 mph covers a mile a minute, which is about 1.6 km a minute.
What is 100 mph in km/h?
100 mph is 160.93 km/h.
How do I convert mph to meters per second?
Multiply by 0.44704. For example, 65 mph × 0.44704 = 29.06 m/s. The factor is exact: 1,609.344 m divided by 3,600 s.
What is the quickest mental conversion from mph to km/h?
Multiply by 1.6, or multiply by 8 and divide by 5. Both run about 0.6% low: 70 mph becomes 112 km/h instead of 112.65.