Speed Converter
Convert between different units of speed including km/h, mph, m/s, knots, feet per second, and Mach number. Get accurate speed conversions for transportation, physics, aviation, and more.
Last updated: 2024-03-22
Understanding Speed Units and Conversion
Our Speed Converter helps you convert between different units of speed and velocity. Speed measurement is essential in many areas including transportation, physics, engineering, and sports. This calculator supports six common speed units: kilometers per hour (km/h), miles per hour (mph), meters per second (m/s), knots, feet per second (ft/s), and Mach number.
| Unit | Symbol | Common Uses |
|---|---|---|
| Kilometers per hour | km/h | Road speed limits in most countries Vehicle speedometers Weather reports (wind speed) |
| Miles per hour | mph | Road speed limits in US, UK Vehicle speedometers in US, UK Sports (baseball, etc.) |
| Meters per second | m/s | Scientific measurements Physics calculations SI unit for velocity |
| Knots | kn | Marine navigation Aviation Meteorology (wind speed) |
| Feet per second | ft/s | Ballistics Fluid mechanics Engineering in US |
| Mach number | Mach | Aviation Supersonic speeds Aerodynamics |
Common Speed Conversions and Their Applications
Here are some common speed conversions and their practical applications:
Some notable speed references:
| Conversion | Exact Value | Common Usage |
|---|---|---|
| 1 km/h to mph | 0.621371 mph | Converting between US and metric road speeds |
| 1 mph to km/h | 1.60934 km/h | International travel, vehicle specifications |
| 1 m/s to km/h | 3.6 km/h | Converting scientific measurements to everyday units |
| 1 knot to km/h | 1.852 km/h | Marine to land speed conversions, weather reports |
| 1 Mach to km/h | 1,235.52 km/h | Aviation, supersonic travel |
- Highway speed limits typically range from 80-130 km/h (50-80 mph)
- Commercial airliners cruise at about 800-900 km/h (500-560 mph)
- The speed of sound (Mach 1) is approximately 343 m/s or 1,235 km/h at sea level
- The International Space Station orbits Earth at approximately 28,000 km/h (17,400 mph)
Understanding the Mach Number
The Mach number represents the ratio of an object's speed to the speed of sound in the surrounding medium. It's named after Austrian physicist Ernst Mach and is particularly important in aerodynamics and supersonic flight.
Mach Number Categories
- Subsonic: Mach < 0.8
- Transonic: 0.8 < Mach < 1.2
- Supersonic: 1.2 < Mach < 5
- Hypersonic: Mach > 5
Important Facts About Mach Number
- The speed of sound varies with altitude, temperature, and medium
- At sea level and standard conditions (15°C, 1 atm), the speed of sound is approximately 343 m/s (1,235 km/h or 767 mph)
- The Concorde cruised at around Mach 2
- Modern fighter jets can reach speeds of Mach 2-3
- The fastest aircraft ever, the NASA X-43A, reached nearly Mach 10
History and Applications of Speed Measurement
Historical Development of Speed Measurement
The measurement of speed has evolved significantly throughout history:
- Ancient civilizations used sundials and water clocks to measure time intervals and estimate speeds
- In the 17th century, scientists began using pendulum clocks for more precise measurements
- The 18th and 19th centuries saw the development of mechanical speedometers for vehicles
- Modern electronic and GPS-based systems now provide highly accurate speed measurements
Practical Applications
Speed measurements are essential in many fields:
- Transportation: Vehicle speedometers, aircraft instruments, maritime navigation
- Sports: Measuring athlete performance, ball speeds, racing times
- Meteorology: Wind speed measurements for weather forecasting
- Physics and Engineering: Fluid dynamics, material testing, ballistics
- Astronomy: Measuring celestial object velocities, calculating orbital mechanics
Understanding Speed Units and Conversion
Our Speed Converter helps you convert between different units of speed and velocity. Speed measurement is essential in many areas including transportation, physics, engineering, and sports. This calculator supports six common speed units: kilometers per hour (km/h), miles per hour (mph), meters per second (m/s), knots, feet per second (ft/s), and Mach number.
| Unit | Symbol | Common Uses |
|---|---|---|
| Kilometers per hour | km/h | Road speed limits in most countries Vehicle speedometers Weather reports (wind speed) |
| Miles per hour | mph | Road speed limits in US, UK Vehicle speedometers in US, UK Sports (baseball, etc.) |
| Meters per second | m/s | Scientific measurements Physics calculations SI unit for velocity |
| Knots | kn | Marine navigation Aviation Meteorology (wind speed) |
| Feet per second | ft/s | Ballistics Fluid mechanics Engineering in US |
| Mach number | Mach | Aviation Supersonic speeds Aerodynamics |
Common Speed Conversions and Their Applications
Here are some common speed conversions and their practical applications:
Some notable speed references:
| Conversion | Exact Value | Common Usage |
|---|---|---|
| 1 km/h to mph | 0.621371 mph | Converting between US and metric road speeds |
| 1 mph to km/h | 1.60934 km/h | International travel, vehicle specifications |
| 1 m/s to km/h | 3.6 km/h | Converting scientific measurements to everyday units |
| 1 knot to km/h | 1.852 km/h | Marine to land speed conversions, weather reports |
| 1 Mach to km/h | 1,235.52 km/h | Aviation, supersonic travel |
- Highway speed limits typically range from 80-130 km/h (50-80 mph)
- Commercial airliners cruise at about 800-900 km/h (500-560 mph)
- The speed of sound (Mach 1) is approximately 343 m/s or 1,235 km/h at sea level
- The International Space Station orbits Earth at approximately 28,000 km/h (17,400 mph)
Understanding the Mach Number
The Mach number represents the ratio of an object's speed to the speed of sound in the surrounding medium. It's named after Austrian physicist Ernst Mach and is particularly important in aerodynamics and supersonic flight.
Mach Number Categories
- Subsonic: Mach < 0.8
- Transonic: 0.8 < Mach < 1.2
- Supersonic: 1.2 < Mach < 5
- Hypersonic: Mach > 5
Important Facts About Mach Number
- The speed of sound varies with altitude, temperature, and medium
- At sea level and standard conditions (15°C, 1 atm), the speed of sound is approximately 343 m/s (1,235 km/h or 767 mph)
- The Concorde cruised at around Mach 2
- Modern fighter jets can reach speeds of Mach 2-3
- The fastest aircraft ever, the NASA X-43A, reached nearly Mach 10
History and Applications of Speed Measurement
Historical Development of Speed Measurement
The measurement of speed has evolved significantly throughout history:
- Ancient civilizations used sundials and water clocks to measure time intervals and estimate speeds
- In the 17th century, scientists began using pendulum clocks for more precise measurements
- The 18th and 19th centuries saw the development of mechanical speedometers for vehicles
- Modern electronic and GPS-based systems now provide highly accurate speed measurements
Practical Applications
Speed measurements are essential in many fields:
- Transportation: Vehicle speedometers, aircraft instruments, maritime navigation
- Sports: Measuring athlete performance, ball speeds, racing times
- Meteorology: Wind speed measurements for weather forecasting
- Physics and Engineering: Fluid dynamics, material testing, ballistics
- Astronomy: Measuring celestial object velocities, calculating orbital mechanics