Speed Converter

Use this free speed converter to convert kilometers per hour (km/h), miles per hour (mph), meters per second (m/s), knots, feet per second and other speed units. Enter a value, select the original unit and choose the target unit to calculate an accurate speed conversion instantly.

Popular Speed Conversions

Quickly calculate popular speed conversions including km/h to mph, mph to km/h, km/h to m/s, m/s to km/h, knots to km/h and knots to mph.

What Is Speed?

Speed describes how quickly an object travels from one location to another. It is calculated as the distance traveled divided by the time required to travel that distance.

Common speed units include kilometers per hour, miles per hour, meters per second, feet per second and knots. The unit used depends on the country, industry and application.

Speed Units Supported

This speed converter supports metric, imperial, nautical and scientific speed measurements.

km/h to mph Converter

The km/h to mph converter is one of the most commonly used speed conversions. Kilometers per hour are widely used for road speed measurements in many countries, while miles per hour are commonly used in the United States and several other locations.

Examples:

• 1 km/h = 0.621371 mph
• 10 km/h = 6.21371 mph
• 50 km/h = 31.06856 mph
• 100 km/h = 62.13712 mph
• 120 km/h = 74.56454 mph

mph to km/h Converter

To convert miles per hour to kilometers per hour, multiply the mph value by 1.609344.

Examples:

• 1 mph = 1.609344 km/h
• 30 mph = 48.28032 km/h
• 50 mph = 80.4672 km/h
• 60 mph = 96.56064 km/h
• 100 mph = 160.9344 km/h

km/h to m/s Converter

Meters per second are commonly used in physics, engineering and scientific calculations. To convert kilometers per hour to meters per second, divide by 3.6.

For example:

m/s to km/h Converter

To convert meters per second to kilometers per hour, multiply the value by 3.6.

Examples:

• 1 m/s = 3.6 km/h
• 5 m/s = 18 km/h
• 10 m/s = 36 km/h
• 20 m/s = 72 km/h
• 30 m/s = 108 km/h

Knots to km/h and mph

A knot is a unit of speed commonly used in aviation, marine navigation, shipping and weather reports. One international knot equals one nautical mile per hour.

To convert knots to kilometers per hour:

To convert kilometers per hour to knots:

mph to m/s Converter

Miles per hour can be converted to meters per second by multiplying the speed by 0.44704.

For example:

Feet per Second to mph and km/h

Feet per second is frequently used in engineering, physics, ballistics and technical measurements.

Common Speed Conversion Chart

Vehicle Speed Converter

Speed conversion is frequently needed when comparing vehicle speed limits, car performance, motorcycle speeds and racing measurements between countries using different measurement systems.

For example, a vehicle traveling at 100 km/h is moving at approximately 62.14 mph.

Running and Cycling Speed Converter

Athletes and fitness users may encounter speed measurements expressed in km/h, mph or meters per second. A speed converter makes it easy to compare running, cycling and training speeds across different measurement systems.

For example:

• 10 km/h ≈ 6.21 mph
• 15 km/h ≈ 9.32 mph
• 20 km/h ≈ 12.43 mph
• 30 km/h ≈ 18.64 mph

Wind Speed Conversion

Wind speed may be reported in knots, kilometers per hour, miles per hour or meters per second. Knots are especially common in marine and aviation applications, while weather services may use different units depending on the country.

This converter can be used to convert numerical wind speeds between km/h, mph, knots and m/s.

Aviation and Marine Speed Converter

Aviation and maritime navigation commonly use knots. One knot is defined as one nautical mile per hour and equals exactly 1.852 kilometers per hour.

Common aviation and marine conversions include:

• knots to km/h
• km/h to knots
• knots to mph
• mph to knots
• knots to m/s
• m/s to knots

Speed Formula

The fundamental formula for calculating speed is:

For example, if a vehicle travels 150 kilometers in 2 hours:

Calculating Distance

Calculating Time

Speed vs Velocity

Speed and velocity are related but are not identical physical quantities. Speed describes the magnitude of motion, while velocity includes both magnitude and direction.

A speed converter converts numerical speed units. It does not determine the direction of motion required for a velocity vector.

How to Use the Speed Converter

1. Enter the speed value.
2. Select the original speed unit.
3. Select the target speed unit.
4. The converted speed is calculated automatically.
5. Use Swap Units to reverse the conversion.
6. Use Copy Result to copy the calculated conversion.

Convert Speed Between Metric, Imperial and Nautical Units

Whether you need a km/h to mph converter, mph to km/h calculator, km/h to m/s converter, m/s to km/h calculator, knots to mph converter, knots to km/h converter or mph to meters per second converter, Smart Unit Calc provides a single tool for common speed conversion requirements.

Speed conversions can be useful for vehicles, road speed limits, running, cycling, aviation, marine navigation, weather observations, engineering, physics and general measurement calculations.

Frequently Asked Questions About Speed Conversion

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