Speed Converter - km/h to mph, knots converter
Convert between km/h, mph, knots, m/s, and Mach. Useful for vehicle speed, wind speed, and aviation.
How to Use the Speed Converter
- Select Source Unit: Choose the speed unit you're converting from (km/h, mph, knots, m/s) from the "From" dropdown.
- Enter Speed Value: Type the speed measurement you want to convert. Enter whole numbers or decimals.
- Choose Target Unit: Select the speed unit you want to convert to from the "To" dropdown menu.
- View Converted Speed: See your converted speed instantly. Useful for vehicle speed limits, wind speed, or aviation calculations.
Speed Conversion Formulas
Kilometers per Hour to Miles per Hour
mph = km/h × 0.621371Example: 100 km/h = 100 × 0.621371 = 62.137 mph
Knots to Kilometers per Hour
km/h = knots × 1.852Example: 10 knots = 10 × 1.852 = 18.52 km/h
Meters per Second to Kilometers per Hour
km/h = m/s × 3.6Example: 10 m/s = 10 × 3.6 = 36 km/h
Speed Conversion Reference Table
| Unit | km/h Equivalent | Common Use | Example |
|---|---|---|---|
| 1 m/s | 3.6 km/h | Scientific, physics | Walking speed |
| 1 km/h | 1 km/h | Vehicle speed (global) | City driving |
| 1 mph | 1.609 km/h | Vehicle speed (US/UK) | Highway speed |
| 1 knot | 1.852 km/h | Aviation, maritime | Aircraft speed |
| 1 Mach | 1,234.8 km/h | Supersonic speed | Sound speed |
Real-World Speed Conversion Examples
Vehicle Speed Limits
Convert speed limits between km/h (used globally) and mph (used in US/UK). A 100 km/h limit equals approximately 62 mph, helping you drive safely when traveling internationally.
Wind Speed
Convert wind speeds for weather forecasts. Meteorologists use different units: km/h, mph, or knots depending on the region. Essential for understanding weather warnings and forecasts.
Aviation Speed
Convert aircraft speeds. Aviation uses knots (nautical miles per hour) as the standard unit for airspeed. Essential for pilots and aviation enthusiasts.
Running & Sports
Convert running speeds and athletic performance metrics. Track your pace in different units for international comparisons and training programs.
Understanding Speed Units
Understanding Speed Units
Speed measures distance traveled per unit of time. Different units developed for different purposes: km/h for road vehicles, mph for US vehicles, knots for navigation, and m/s for scientific calculations. Each unit has its advantages for specific applications.
Why Knots?
Knots (nautical miles per hour) are used in aviation and maritime navigation because nautical miles are based on the Earth's latitude, making navigation calculations more accurate. One nautical mile equals one minute of latitude, simplifying chart work and navigation.
Mach Number
Mach measures speed relative to the speed of sound. Mach 1 equals the speed of sound (approximately 343 m/s or 1,234.8 km/h at sea level). Used for supersonic aircraft. Mach speed varies with altitude and temperature - sound travels faster at higher temperatures.
Speed Conversion Tips
- For quick mental conversion: 1 km/h ≈ 0.6 mph (divide by 1.6)
- 1 knot = 1.852 km/h (exact conversion for navigation)
- Speed of sound (Mach 1) varies with altitude and temperature
- When driving internationally, always check speed limits in local units
- Wind speed: 1 m/s = 3.6 km/h = 2.237 mph