Speed Converter
Convert between km/h, mph, m/s, knots, ft/s, and Mach number instantly.
1 Kilometers/hour equals…
| Unit | Value |
|---|---|
| Meters/second (m/s) | 0.27777778 |
| Kilometers/hour (km/h) | 1 |
| Miles/hour (mph) | 0.62137119 |
| Knot (kn) | 0.53995727 |
| Feet/second (ft/s) | 0.91134442 |
| Mach (Mach) | 0.00080984775 |
Click any row to set it as the target unit.
About the Speed Converter
Speed is expressed in different units depending on context: km/h for road vehicles, m/s for physics and engineering, miles per hour for US/UK vehicles, and knots for aviation and maritime. India uses km/h for speed limits and vehicle speedometers. International driving, air travel, weather, and physics problems all require quick speed conversions.
Speed Conversion Reference
1 km/h = 0.2778 m/s = 0.6214 mph · 1 mph = 1.609 km/h · 1 knot = 1.852 km/h
Speed of sound: 343 m/s = 1,235 km/h at sea level · Speed of light: 299,792 km/s · Highway limit India: 120 km/h = 74.6 mph · Cyclone classification: >89 km/h (severe), >118 km/h (very severe)
Worked Example
Driving in UK, speed limit 70 mph - how fast is that in km/h?
70 mph × 1.609 = 112.7 km/h · Just under Indian highway limit of 120 km/h
Tips & Insights
- 1
Weather reports in the US use mph; Indian weather (IMD) uses km/h. Cyclone wind speeds are in km/h in India.
- 2
Physics problems and fluid mechanics always use m/s. Always convert km/h to m/s for calculations.
- 3
Aviation uses knots (nautical miles per hour) universally. 1 knot = 1.852 km/h = 1.151 mph.
Why this matters for you
Speed unit errors in engineering and navigation have caused real accidents. For everyday users, knowing that a UK 'National Speed Limit' of 70 mph = 112 km/h prevents inadvertently speeding (or under-driving) when renting a car abroad. Weather alerts in knots or mph become immediately meaningful when you can convert to km/h.
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