Speed Unit Conversion: km/h to mph and m/s Explained
2025-08-15 3 min read
Convert between kilometres per hour, miles per hour, metres per second, and knots with exact formulas, a conversion table, and real-world reference speeds.
Speed units vary by context — cars use km/h or mph, physics uses m/s, aviation uses knots, and athletes track pace in min/km. Understanding conversions between them is useful for travel, sports, and science.
Common Speed Units
- km/h (kilometres per hour): Standard for road speed in most of the world
- mph (miles per hour): Used in USA, UK for road speed
- m/s (metres per second): Physics standard
- knots (nautical miles per hour): Aviation and maritime
Conversion Factors
- 1 km/h = 0.62137 mph
- 1 mph = 1.60934 km/h
- 1 m/s = 3.6 km/h
- 1 knot = 1.852 km/h = 1.15078 mph
Speed Reference Points
- Walking: 5 km/h (3.1 mph)
- Cycling: 20–30 km/h (12–19 mph)
- City speed limit: 50 km/h (31 mph)
- Highway speed limit: 100–130 km/h (62–81 mph)
- Bullet train (Shinkansen): 320 km/h (199 mph)
- Commercial airplane: 900 km/h (560 mph, Mach 0.85)
- Speed of sound: 343 m/s = 1,235 km/h at 20°C
- Speed of light: 299,792 km/s ≈ 1.08 billion km/h
Running Pace Conversion
Running pace (min/km) is the inverse of speed. A pace of 5:00/km = 12 km/h. Formula: speed (km/h) = 60 / pace (min/km). 5:30/km = 60/5.5 = 10.9 km/h ≈ 6.8 mph.
Convert speed units with our Speed Converter tool.