Converter for speed
Convert between miles per hour (mph), kilometers per hour (km/h), meters per second (m/s), knots and feet per second (ft/s). Type in any box—the other value updates instantly.
Quick speed converters
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MPH ↔ KPH
1 mph = 1.609344 km/h
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MPH ↔ m/s
1 mph = 0.44704 m/s
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KPH ↔ m/s
1 km/h = 0.2777777778 m/s
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Knots ↔ MPH
1 knot = 1.150779448 mph
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Knots ↔ KPH
1 knot = 1.852 km/h
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ft/s ↔ m/s
1 ft/s = 0.3048 m/s
Common speed conversions (examples)
| MPH | KM/H |
|---|---|
| 5 | 8.05 |
| 10 | 16.09 |
| 30 | 48.28 |
| 50 | 80.47 |
| 60 | 96.56 |
| 70 | 112.65 |
| 100 | 160.93 |
How speed conversions work
The base SI unit for speed is meters per second (m/s). Many everyday speeds are expressed in kilometers per hour (km/h) or miles per hour (mph), while aviation and maritime contexts often use knots (nautical miles per hour). Exact factors:
- 1 mph = 1.609344 km/h = 0.44704 m/s
- 1 km/h = 0.621371192 mph = 0.2777777778 m/s
- 1 m/s = 3.6 km/h = 2.2369362921 mph
- 1 knot = 1.852 km/h = 0.514444 m/s = 1.150779448 mph
- 1 ft/s = 0.3048 m/s
We use these precise constants so your results are accurate to many decimal places. The visible rounding is just for readability.
All speed converters
Speed conversion FAQs
What is the fastest way to convert mph to km/h?
Multiply mph by 1.609344. For a quick mental estimate, multiply by 1.6.
How do I convert km/h to m/s?
Divide km/h by 3.6. Example: 90 km/h ÷ 3.6 = 25 m/s.
What is a knot?
A knot is one nautical mile per hour. 1 knot = 1.852 km/h ≈ 1.151 mph.
How many ft/s is 60 mph?
60 mph ≈ 88.0 ft/s (since 1 mph ≈ 1.46667 ft/s).