Speed Converter
Convert between km/h, mph, and other speed units
Common Speed Conversions
Conversion Formulas
Kilometers per Hour to Miles per Hour:
mph = km/h × 0.621371
Miles per Hour to Kilometers per Hour:
km/h = mph × 1.60934
Common Use Cases
- • Converting speed limits when traveling internationally
- • Understanding vehicle speedometers in different units
- • Comparing running or cycling speeds
- • Converting weather wind speeds
Privacy & Security
All speed conversions are performed locally in your browser. No speed data, location information, or usage is stored or transmitted. Your conversions remain completely private.
About the Speed Converter
Our speed converter helps you translate velocity measurements between different units used worldwide. Whether you're traveling internationally and need to understand road speed limits, comparing vehicle specifications, calculating running pace, understanding wind speeds, or working with aviation speeds, this tool provides instant conversions. Convert between kilometers per hour (km/h), miles per hour (mph), meters per second (m/s), knots, feet per second, and more. Quick presets for common speeds make frequent conversions even faster.
Key Features
Multiple Speed Units
km/h, mph, m/s, knots, ft/s, and more velocity units
Real-Time Conversion
See results instantly as you type
Common Speed Presets
Quick buttons for typical speeds (50, 60, 100, 120 km/h)
Bi-Directional
Convert from any unit to any other seamlessly
High Precision
Accurate calculations for technical applications
Speed Limit Reference
Compare with typical speed limits in different countries
Copy Results
One-click copy of converted values
All Units Display
View speed in all available units simultaneously
How to Convert Speed
Enter Speed Value
Type the speed you want to convert (or use preset buttons)
Select From Unit
Choose the unit you're converting from (km/h, mph, m/s, etc.)
Select To Unit
Choose the unit you want to convert to
View Results
See instant conversion with all related speed units
Speed Conversion Tips
- km/h to mph Quick Math: Multiply km/h by 0.6 for rough mph estimate (exact: 0.621371)
- mph to km/h Quick Math: Multiply mph by 1.6 for rough km/h estimate (exact: 1.609344)
- Common Speed Limits: US interstate: 65-75 mph = 105-120 km/h. European motorway: 120-130 km/h = 75-80 mph
- Knots Explained: Used in aviation/maritime. 1 knot = 1 nautical mile/hour = 1.852 km/h = 1.151 mph
- m/s for Physics: 1 m/s = 3.6 km/h = 2.237 mph. Useful for physics problems and scientific calculations
- Running Pace: 5 min/km pace ≈ 12 km/h ≈ 7.5 mph. 8 min/mile pace ≈ 7.5 mph ≈ 12 km/h
Frequently Asked Questions
How many mph is 100 km/h?
100 km/h equals 62.137 mph (approximately 62 mph). This is a commonly asked conversion because many European highways have 100-120 km/h speed limits, and travelers want to know how fast that is in mph. 120 km/h is about 75 mph.
What's the difference between mph and knots?
mph (miles per hour) uses statute miles, while knots use nautical miles per hour. 1 knot = 1.15078 mph. Knots are standard in aviation and maritime because nautical miles relate directly to latitude (1 nautical mile = 1 minute of latitude), making navigation calculations easier.
Why do different countries use different speed units?
Most countries use km/h (metric system), while the US and UK road signs use mph (imperial system). Aviation uses knots worldwide. Scientific work often uses m/s (meters per second). These differences stem from historical measurement system adoption, making speed converters essential for international travel and work.
How fast is 60 mph in km/h?
60 mph equals 96.56 km/h (approximately 97 km/h). This is useful for Americans visiting metric countries, as 60 mph is a common US highway speed. Note that many metric countries have 90 km/h or 100 km/h limits on similar roads.
What is m/s used for?
Meters per second (m/s) is the SI unit for velocity, used in physics, engineering, and scientific calculations. While less intuitive for everyday speeds, it's essential for technical work. For reference, 100 km/h = 27.78 m/s, and walking speed is about 1.4 m/s.
How do I convert running pace to speed?
Running pace (min/km or min/mile) is inverse of speed. For 5 min/km pace: 60 ÷ 5 = 12 km/h. For 8 min/mile: 60 ÷ 8 = 7.5 mph. Slower pace numbers mean faster speeds. Many running apps show pace, but speed converters help compare with cycling or driving speeds.
Why Use a Speed Converter?
Speed units vary globally, creating confusion for travelers, vehicle shoppers, and professionals. Understanding foreign speed limits prevents tickets and accidents. Comparing vehicle specs from different countries requires conversion (European cars list top speed in km/h, American in mph). Athletes need to convert between pace and speed, or compare training speeds across different units. Aviation and maritime professionals constantly work with knots. Rather than memorizing conversion factors or risking calculation errors, a speed converter provides instant, accurate results for any velocity conversion need, enhancing safety, understanding, and decision-making.