What is a Speed Converter?
A speed converter transforms velocity measurements from one unit to another. Speed (or velocity in physics) is the rate of change of position, measuring how fast an object moves over time.
This converter supports km/h (metric), mph (imperial), m/s (scientific), knots (nautical/aviation), and Mach (supersonic speeds).
Conversion Formulas
1 km/h = 0.621371 mph = 0.277778 m/s
1 mph = 1.60934 km/h = 0.44704 m/s
1 m/s = 3.6 km/h = 2.23694 mph
1 knot = 1.852 km/h = 1.15078 mph
Mach 1 ≈ 1,235 km/h = 767 mph (at sea level)
Common Speed Reference Points
- Walking Speed: ~5 km/h (~3 mph)
- Running Speed: ~15 km/h (~9 mph)
- Highway Speed Limit: 100-120 km/h (60-75 mph)
- Commercial Aircraft: ~900 km/h (~560 mph, ~Mach 0.8)
- Speed of Sound: 1,235 km/h (767 mph, Mach 1)
Frequently Asked Questions
How do I convert km/h to mph quickly?
Multiply by 0.6 for a quick estimate, or divide by 1.6 for slightly better accuracy. For example, 100 km/h ÷ 1.6 ≈ 62 mph. The exact factor is 0.621371.
What is a knot and why is it used?
A knot equals one nautical mile per hour (1.852 km/h). It's used in maritime and aviation because nautical miles relate directly to latitude (1 nautical mile = 1 minute of latitude), making navigation easier.
How fast is Mach 2?
Mach 2 is twice the speed of sound, approximately 2,470 km/h (1,534 mph). The Concorde cruised at about Mach 2. Note that Mach speed varies with altitude and temperature.