Speed converter
Convert driving, wind and running speeds. One mile per hour is exactly 0.447 04 m/s.
1 mile per hour = 1.6093 kilometres per hour
How it’s calculated
km/h = mph × 1.609344
- Multiply the value in miles per hour by 1.609344.
- To go back, divide by 1.609344 (or multiply by 0.6213711922).
- 1 mph = 1.609344 km/h · 1 km/h = 0.6213711922 mph
Show worked solutionFactor, unit cancellation and rounding, step by step
Find the conversion factor
By definition 1 mph = 0.44704 m/s and 1 km/h = 0.277777777777778 m/s, so 1 mph = 1.609344 km/h. Source: NIST SP 811 / Handbook 44; BIPM SI Brochure (9th ed.) (SI prefixes and accepted units).
Multiply by the factor written as a fraction
Put mph in the denominator so it cancels, leaving km/h.
Calculate (unrounded)
Round the answer
Rounded to 5 significant figures.
Answer: 1.6093 km/h
1 mph in other units
Batch convert mph → km/h
- 1 mph = 1.6093 km/h
- 5 mph = 8.0467 km/h
- 10 mph = 16.093 km/h
- 25 mph = 40.234 km/h
Common speed conversions
Speed units and exact definitions
| Unit | System | Definition |
|---|---|---|
| Kilometre per hour (km/h) | metric (non-SI) | 1 km/h = 0.2777777778 m/s |
| Mile per hour (mph) | US & imperial (identical) | 1 mph = 0.44704 m/s |
| Metre per second (m/s) | SI (metric) | Base unit |
| Knot (kn) | other | 1 kn = 0.5144444444 m/s |
| Foot per second (ft/s) | US & imperial (identical) | 1 ft/s = 0.3048 m/s |
| Speed of light (c) | other | 1 c = 299792458 m/s |
Miles per hour to kilometres per hour conversion table
| Miles per hour (mph) | Kilometres per hour (km/h) |
|---|---|
| 0.1 mph | 0.16093 km/h |
| 0.5 mph | 0.80467 km/h |
| 1 mph | 1.6093 km/h |
| 2 mph | 3.2187 km/h |
| 3 mph | 4.828 km/h |
| 4 mph | 6.4374 km/h |
| 5 mph | 8.0467 km/h |
| 6 mph | 9.6561 km/h |
| 7 mph | 11.265 km/h |
| 8 mph | 12.875 km/h |
| 9 mph | 14.484 km/h |
| 10 mph | 16.093 km/h |
| 15 mph | 24.14 km/h |
| 20 mph | 32.187 km/h |
| 25 mph | 40.234 km/h |
| 30 mph | 48.28 km/h |
| 40 mph | 64.374 km/h |
| 50 mph | 80.467 km/h |
| 75 mph | 120.7 km/h |
| 100 mph | 160.93 km/h |
| 250 mph | 402.34 km/h |
| 500 mph | 804.67 km/h |
| 1,000 mph | 1,609.3 km/h |
Frequently asked questions
Which speed units can I convert?
kilometres per hour (km/h), miles per hour (mph), metres per second (m/s), knots (kn), feet per second (ft/s), × speed of light (c).
How accurate are the results?
Every unit is stored with its exact defining factor (NIST SP 811, NIST Handbook 44 or the BIPM SI Brochure). Calculations use double-precision arithmetic and are rounded only for display, to 5 significant figures by default (trailing zeros dropped, so 1 km shows as 1000 m). You can choose Auto (up to 10 digits), fixed decimals or more significant figures, or switch to scientific or engineering notation.