Speed Converter
Convert speeds between mph, km/h, m/s, knots, and Mach
Speed
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Frequently Asked Questions
How do I convert mph to km/h?
Multiply mph by 1.60934. Example: 60 mph = 60 × 1.60934 = 96.56 km/h. To convert km/h to mph: divide by 1.60934 (or multiply by 0.6214). Quick mental estimate: km/h ≈ mph × 1.6 (or mph × 8/5).
What is a knot in speed?
1 knot = 1 nautical mile per hour = 1.852 km/h = 1.151 mph. Knots are used in aviation and maritime navigation because nautical miles correspond to degrees of latitude (1 nautical mile = 1 arcminute of latitude), making navigation easier. A hurricane is Category 1 at 64-82 knots (74-95 mph).
What is Mach 1?
Mach 1 = the speed of sound in air, approximately 343 m/s = 1,235 km/h = 767 mph at sea level (15 degrees C). Mach number = object speed / speed of sound. Subsonic: Mach < 1. Transonic: Mach 0.8-1.2. Supersonic: Mach 1-5. Hypersonic: Mach 5+. The exact value varies with temperature and altitude.
How fast is the fastest car, plane, and runner?
Fastest production car (2024): Bugatti Bolide ~500 km/h (311 mph). Fastest jet aircraft: SR-71 Blackbird at Mach 3.3 (3,540 km/h, 2,200 mph). Fastest human runner: Usain Bolt at 44.72 km/h (27.79 mph) in 2009. International Space Station: 28,000 km/h (17,500 mph).
What is escape velocity?
Escape velocity is the speed needed to break free from a celestial body gravity without further propulsion. Earth: 11.2 km/s = 40,320 km/h = 25,054 mph. Moon: 2.38 km/s. Mars: 5.03 km/s. Jupiter: 59.5 km/s. The Sun: 617.5 km/s. Rockets do not need to reach this instantly — they can use thrust continuously.
Speed Conversion Table
| mph | km/h | m/s | knots |
|---|---|---|---|
| 10 | 16.1 | 4.5 | 8.7 |
| 30 | 48.3 | 13.4 | 26.1 |
| 55 | 88.5 | 24.6 | 47.8 |
| 65 | 104.6 | 29.1 | 56.5 |
| 75 | 120.7 | 33.5 | 65.2 |
| 100 | 160.9 | 44.7 | 86.9 |
| 200 | 321.9 | 89.4 | 173.8 |