Speed Converter
Convert between mph, km/h, m/s, knots and Mach. As a quick guide, 100 km/h is about 62 mph.
Speed
To convert m/s to km/h, multiply by 3.6.
Distance Finder
Enter a speed and pick a distance unit to see how far you'd travel over time (distance = speed × time).
| Time | Meters |
|---|---|
| Enter a speed above to see the distance travelled. | |
Figures assume constant speed on a straight path. Mach is calculated at sea level (speed of sound ≈ 343 m/s).
Speed Explained: Units, History, and How Speed Measurement Works
Speed is a fundamental concept in physics and everyday life, measuring how fast an object moves over a certain distance in a given amount of time. From transportation and sports to science and engineering, speed plays a crucial role in understanding motion. Common speed units include kilometers per hour (KPH), miles per hour (MPH), and meters per second (m/s).
What Is Speed?
Speed is defined as the distance traveled divided by the time taken. It is a key concept in classical mechanics and is used to describe how quickly an object moves.
Formula
Speed = Distance ÷ Time
Example: A car travelling 100 km in 2 hours has a speed of 50 km/h.
Common Units of Speed
Kilometers per Hour (km/h or KPH)
The standard unit of speed in most metric countries. Widely used for road speed limits and transportation across Europe and much of the world.
Miles per Hour (mph)
Commonly used in countries that follow the imperial system, including the United States and the United Kingdom. Standard for road speeds and vehicle speedometers.
Meters per Second (m/s)
The SI (International System of Units) standard for speed. Widely used in physics calculations and scientific research.
Knots (kn)
Used in aviation and maritime navigation. 1 knot equals 1 nautical mile per hour.
Feet per Second (ft/s)
Used in engineering and physics in some regions.
How Speed Measurement Works
Speed is calculated by measuring distance and time accurately. Modern technology has made this process highly precise:
- Speedometers in vehicles measure wheel rotation to estimate speed
- Radar guns use radio waves to detect vehicle speed
- GPS systems calculate speed based on changes in location over time
Why Speed Is Important
Transportation
Ensuring safe driving and travel
Sports
Tracking performance and records
Science and Engineering
Studying motion and designing systems
Aviation and Maritime
Navigating long distances accurately
Speed vs Velocity: What's the Difference?
While often used interchangeably, speed and velocity are different concepts in physics:
- Speed is how fast something moves
- Velocity includes both speed and direction
For example, 60 km/h north is a velocity, while 60 km/h alone is speed.
Convert speed between mph, km/h, knots, and meters per second — for driving, aviation, sailing, and sports.
Formula
1 mph = 1.609 km/h. 1 knot = 1.852 km/h. 1 m/s = 3.6 km/h.
Reference Values
- •60 mph = 96.56 km/h
- •1 knot = 1.151 mph
- •1 m/s = 3.6 km/h
FAQ
Common questions about Speed Converter
How we calculate this
We use the standard published formula for this calculation, and we show the working so you can check it.
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