Speed Converter
Convert between mph, km/h, knots, meters per second, and other speed units instantly.
How to Use the Speed Converter
- Enter Speed Value: Input the speed you want to convert
- Select From Unit: Choose the unit you're converting from (mph, km/h, knots, etc.)
- Select To Unit: Choose the unit you want to convert to
- Swap Units: Use the swap button to quickly reverse the conversion
- View Results: See instant conversion results in your target unit
Speed Units Explained
Miles Per Hour (MPH)
Standard speed unit in the United States and UK for road travel. Speed limits, vehicle speedometers, and road signs use mph in these countries. One mile equals 1.609 kilometers, so mph is slower than km/h by this factor.
Kilometers Per Hour (KPH)
Metric speed unit used globally except in the US and UK. Canada, Europe, Australia, and most countries use km/h for speed limits and vehicle speeds. Easier for calculation since it aligns with the metric system (1 km = 1000 meters).
Knots (Nautical Miles Per Hour)
Aviation and maritime standard speed unit. One knot equals one nautical mile per hour, about 1.15 mph or 1.85 km/h. Aircraft speeds, wind speeds, and ship speeds use knots. Based on Earth's latitude, making it ideal for navigation and weather reporting.
Meters Per Second (m/s)
Scientific and physics standard for velocity. Used in research, engineering, and technical specifications. Simple metric unit where 1 m/s equals 3.6 km/h. Wind speed measurements often use m/s in scientific contexts and weather stations.
Common Speed Conversions
Road Travel
- • 60 mph = 96.6 km/h (typical highway speed in US)
- • 100 km/h = 62.1 mph (common speed limit in metric countries)
- • 30 mph = 48.3 km/h (residential area speed limit)
Aviation
- • 500 knots = 575 mph = 926 km/h (cruising speed for commercial jets)
- • 100 knots = 115 mph = 185 km/h (small aircraft speed)
- • Mach 1 = 767 mph = 1,234 km/h = 661 knots (speed of sound at sea level)
Weather and Science
- • 10 m/s = 36 km/h = 22.4 mph (strong breeze wind speed)
- • 25 m/s = 90 km/h = 56 mph (gale force winds)
- • 50 m/s = 180 km/h = 112 mph (severe storm winds)
Practical Applications
Travel and Navigation
Convert speed limits when driving in foreign countries. GPS devices may show speed in different units than road signs. Understanding both mph and km/h helps avoid speeding tickets abroad and calculate accurate travel times across different regions.
Sports and Fitness
Running pace, cycling speed, and swimming velocity use various units. Convert m/s to mph for treadmill settings, or km/h to mph for bike computer readings. Race results often list speeds in different units depending on country and sport.
Aviation and Marine
Pilots and sailors must understand knots for navigation, weather reports, and aircraft/vessel performance. Flight plans, nautical charts, and aviation weather all use knots as the standard unit. Converting to mph or km/h helps passengers understand travel speed.
Engineering and Physics
Scientific calculations require m/s for consistency with SI units. Engineering specifications, vehicle testing, and physics experiments measure velocity in m/s. Converting to mph or km/h makes results meaningful for practical applications and consumer understanding.
Frequently Asked Questions
How do I convert mph to km/h?
Multiply mph by 1.609 to get km/h. For example: 60 mph × 1.609 = 96.54 km/h. To convert km/h to mph, divide by 1.609 or multiply by 0.621.
Why do aircraft use knots instead of mph?
Knots are based on nautical miles, which relate directly to latitude and longitude on Earth. One nautical mile equals one minute of latitude, making navigation calculations simpler for pilots and sailors.
What's the difference between speed and velocity?
Speed is how fast something moves (scalar quantity). Velocity includes direction (vector quantity). This converter measures speed magnitude, regardless of direction.
Are the conversions accurate for scientific use?
Yes, our converter uses precise conversion factors and provides accuracy suitable for scientific, engineering, and professional applications.