Speed Converter

Our Speed Converter is a versatile tool that helps you convert between different units of speed: kilometers per hour (km/h), miles per hour (mph), meters per second (m/s), and knots (kts). Whether you’re analyzing vehicle speeds, working with scientific data, planning marine navigation, or comparing sports performance, this calculator makes speed conversion simple and accurate.

Understanding Speed Units

Kilometers per Hour (km/h)

The kilometer per hour is the most commonly used unit of speed in most countries worldwide. It represents the number of kilometers traveled in one hour and is the standard unit for vehicle speeds in most nations using the metric system.

Miles per Hour (mph)

Miles per hour is the standard unit of speed in the United States and some other countries. It represents the number of miles traveled in one hour and is commonly used for vehicle speeds, wind speeds, and other measurements in countries using the imperial system.

Meters per Second (m/s)

Meters per second is the SI unit of speed, commonly used in physics and scientific calculations. It represents the distance in meters traveled in one second and is particularly useful for scientific work and calculations involving acceleration and velocity.

Knots (kts)

A knot is a unit of speed equal to one nautical mile per hour, primarily used in marine navigation and aviation. One knot is approximately 1.852 kilometers per hour or 1.15078 miles per hour.

Conversion Formulas

Here are the formulas used for converting between different speed units:

Kilometers per Hour Conversions

1 km/h = 0.621371 mph
1 km/h = 0.277778 m/s
1 km/h = 0.539957 knots

Miles per Hour Conversions

1 mph = 1.60934 km/h
1 mph = 0.44704 m/s
1 mph = 0.868976 knots

Meters per Second Conversions

1 m/s = 3.6 km/h
1 m/s = 2.23694 mph
1 m/s = 1.94384 knots

Knots Conversions

1 knot = 1.852 km/h
1 knot = 1.15078 mph
1 knot = 0.514444 m/s

Common Speed References

Here are some common speed measurements for reference:

Average walking speed: 5 km/h (3.1 mph)
Typical city speed limit: 50 km/h (31 mph)
Highway speed limit (US): 65-75 mph (105-120 km/h)
Commercial aircraft cruising speed: 450-500 knots (833-926 km/h)
Speed of sound at sea level: 343 m/s (1,235 km/h)

How to Use the Calculator

Enter a speed value in any of the four input fields (km/h, mph, m/s, or knots)
The calculator will automatically convert and display the equivalent speeds in all other units
Use the Reset button to clear all fields and start a new conversion
Hover over the input fields for helpful tooltips

Applications

Speed conversion is essential in many fields:

Transportation: Converting between mph and km/h for international travel
Aviation: Working with knots and other speed measurements
Marine Navigation: Converting between knots and other units
Sports Science: Analyzing athlete performance in different units
Physics: Converting between m/s and other units for calculations
Weather Forecasting: Converting wind speeds between different units

Tips for Accurate Conversion

Always use decimal points for precise measurements
Double-check critical measurements
Consider rounding to appropriate precision for your application
Keep in mind the context of your measurement needs

Technical Notes

This calculator provides conversions accurate to two decimal places, which is sufficient for most practical purposes. For extremely precise measurements or scientific applications, please use specialized measuring equipment and conversion methods.

Common Conversion Scenarios

Road Travel
- Converting speed limits between countries
- Understanding vehicle specifications
- Calculating travel times
Marine and Aviation
- Converting between knots and km/h
- Flight planning calculations
- Marine navigation
Sports and Athletics
- Converting running speeds
- Analyzing performance metrics
- Comparing international records

Remember to always verify critical measurements, especially in transportation, aviation, or safety-related applications. While this calculator is accurate for general use, professional applications may require additional precision or verification.