Speed Conversion - Convert Kilometers per Hour, Miles per Hour, and More

Speed Converter

Convert speed measurements between different units quickly and accurately

Convert Speed

Understanding Speed Measurements

Speed conversions are essential for various applications, from transportation and sports to scientific research and engineering. Understanding speed conversions ensures accurate and consistent results across different measurement systems and scales.

Common Speed Units

Metric Units

  • Meters per Second (m/s)
  • Centimeters per Second (cm/s)
  • Millimeters per Second (mm/s)
  • Kilometers per Hour (km/h)
  • Kilometers per Second (km/s)

Imperial & Other Units

  • Miles per Hour (mph)
  • Feet per Second (ft/s)
  • Inches per Second (in/s)
  • Knots (kn)
  • Mach (M)

Common Applications

FieldMeasurement TypesTypical Uses
TransportationKilometers per Hour, Miles per HourVehicle speed, traffic management
SportsMeters per Second, Kilometers per HourAthletic performance, race timing
AviationKnots, MachAircraft speed, flight planning
Scientific ResearchCentimeters per Second, Millimeters per SecondLaboratory measurements, material testing
Space & AstronomyKilometers per SecondOrbital velocities, space missions
EngineeringMeters per Second, Inches per SecondMachinery, precision instruments
Everyday UseKilometers per Hour, Miles per HourWalking speed, cycling

Conversion Tips

  • 1 km/h equals approximately 0.621371 mph
  • 1 mph equals approximately 1.609344 km/h
  • 1 m/s = 100 cm/s = 1000 mm/s
  • 1 km/s = 1000 m/s (orbital and escape velocities)
  • Remember that 1 knot = 1.15078 miles per hour
  • Speed is always a ratio of distance to time

Speed Conversions

ConversionFormula/RuleQuick Answer
Kilometers per Hour to Miles per Hour1 mph = 1.609344 km/hDivide km/h by 1.609344
Miles per Hour to Kilometers per Hour1 km/h = 0.621371 mphMultiply mph by 1.609344
Meters per Second to Kilometers per Hour1 km/h = 0.277778 m/sMultiply m/s by 3.6
Kilometers per Hour to Meters per Second1 m/s = 3.6 km/hDivide km/h by 3.6
Meters per Second to Centimeters per Second1 m/s = 100 cm/sMultiply m/s by 100
Centimeters per Second to Meters per Second1 cm/s = 0.01 m/sDivide cm/s by 100
Kilometers per Second to Meters per Second1 km/s = 1000 m/sMultiply km/s by 1000
Knots to Miles per Hour1 mph = 0.868976 knMultiply kn by 1.15078
Miles per Hour to Knots1 kn = 1.15078 mphDivide mph by 1.15078
Mach to Miles per Hour1 mph = 0.00130332 MMultiply M by 767.269
Miles per Hour to Mach1 M = 767.269 mphDivide mph by 767.269

Our comprehensive speed conversion tool provides accurate conversions between all major speed units, from scientific measurements to everyday applications. Whether you're working in transportation, sports, engineering, or scientific research, our converter ensures precise speed conversions across all scales.

Speed Conversion Questions

Everything you need to know about speed measurements and conversions

What is the difference between speed and velocity?

Speed is a scalar quantity representing how fast an object is moving, regardless of direction. Velocity is a vector quantity that includes both speed and direction.

Why are there so many different speed units?

Different regions and industries use different units based on tradition and application. For example, km/h is common in most countries, mph in the US and UK, knots in aviation and maritime, cm/s in scientific research, and km/s in space applications.

How do I convert between km/h and mph?

To convert km/h to mph, multiply by 0.621371. To convert mph to km/h, multiply by 1.609344.

When are cm/s and mm/s used?

Centimeters per second (cm/s) and millimeters per second (mm/s) are commonly used in scientific research, laboratory measurements, material testing, and precision engineering where smaller-scale measurements are needed.

What is km/s used for?

Kilometers per second (km/s) is used in astronomy and space science for measuring orbital velocities, escape velocities, and spacecraft speeds. For example, Earth's orbital speed around the Sun is about 30 km/s.

What is Mach and when is it used?

Mach is a dimensionless unit representing the ratio of an object's speed to the speed of sound in air. It's used in aviation and aerospace to describe supersonic and hypersonic speeds. Mach 1 is the speed of sound (about 340.29 m/s at sea level).

Why do ships and planes use knots?

Knots are used in aviation and maritime navigation because they directly relate to nautical miles, which are based on the Earth's circumference. 1 knot = 1 nautical mile per hour (1.852 km/h).

What are typical speed limits for vehicles?

Speed limits vary by country and road type. Common limits: 50 km/h (urban), 90 km/h (rural), 120-130 km/h (motorways) in Europe; 25-35 mph (urban), 55-75 mph (highways) in the US. Always follow local regulations.

How is wind speed measured?

Wind speed is measured using anemometers and reported in km/h, mph, or knots. Meteorological agencies use the Beaufort scale to describe wind force based on observed conditions.

What is the fastest speed ever recorded by a human-made object?

The Parker Solar Probe, launched by NASA, is the fastest human-made object, reaching speeds over 692,000 km/h (430,000 mph or about 192 km/s) as it approaches the Sun.

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