Kilometer Per Hour

Team Physics -
Created by: Team Physics -, Last Updated: April 25, 2024

Kilometer Per Hour

In physics, speed is a scalar quantity that describes how fast an object is moving, while velocity is a vector quantity that describes the speed of an object in a given direction. The concept of kilometer per hour applies to both speed and velocity in everyday use, although it technically refers to speed since it does not specify direction.

What is Kilometer Per Hour?

Kilometer Per Hour (km/h) is a unit of speed indicating the distance in kilometers traveled in one hour. Widely used in transportation and road systems, it measures how fast an object moves. In physics, this unit helps in analyzing motion-related problems, converting readily to meters per second (m/s) for scientific calculations.

Kilometer Per Hour Formula and Symbol

The symbol for kilometer per hour is km/h. This unit indicates the number of kilometers traveled in one hour.

The formula to determine speed in kilometers per hour is:

Speed (km/h) = Distance (km)/Time (hours)

This equation calculates speed by dividing the distance traveled in kilometers by the time it took to travel that distance in hours.

Conversion of Kilometer Per Hour into Other Units

From/To UnitConversion Formula
Kilometer per Hour to Meters per Second (km/h to m/s)1 km/h = 0.27778 m/s
Kilometer per Hour to Miles per Hour (km/h to mph)1 km/h ≈ 0.621371 mph
Kilometer per Hour to Feet per Second (km/h to fps)1 km/h ≈ 0.911344 fps
Kilometer per Hour to Knots (km/h to knots)1 km/h ≈ 0.539957 knots
Kilometer per Hour to Centimeters per Second (km/h to cm/s)1 km/h ≈ 277.78 cm/s

Kilometer Per Hour (km/h) to Meters per Second (m/s)

1 Kilometer Per Hour (km/h) = 0.27778 Meters per Second (m/s)

One kilometer per hour (km/h) is equivalent to approximately 0.27778 meters per second (m/s), making it a straightforward unit for converting larger scale speeds to finer measurements.

Kilometer Per Hour (km/h) to Miles per Hour (mph)

1 Kilometer Per Hour (km/h) ≈ 0.621371 Miles per Hour (mph)

1 Kilometer Per Hour (km/h) is approximately equal to 0.621371 Miles per Hour (mph), a conversion used to translate speed from metric to imperial units.

Kilometer Per Hour (km/h) to Feet per Second (fps)

1 Kilometer Per Hour (km/h) ≈ 0.911344 Feet per Second (fps)

One kilometer per hour (km/h) is approximately equal to 0.911344 feet per second (fps), used to convert road speeds into a unit familiar in the United States.

Kilometer Per Hour (km/h) to Knots (knots)

1 Kilometer Per Hour (km/h) ≈ 0.539957 Knots (knots)

One kilometer per hour (km/h) is approximately equal to 0.539957 knots, a unit commonly used to measure speeds in maritime and air navigation.

Kilometer Per Hour (km/h) to Centimeters per Second (cm/s)

1 Kilometer Per Hour (km/h) ≈ 277.78 Centimeters per Second (cm/s)

Converting 1 kilometer per hour (km/h) to centimeters per second results in approximately 277.78 cm/s, useful for precise measurements in scientific and engineering applications.

Kilometer Per Hour Unit

1 kilometer per hour (km/h) = 27.7778 centimeters per second (cm/s) approximately.

This conversion can be derived from the fact that 1 kilometer equals 100,000 centimeters and 1 hour equals 3600 seconds. Therefore:

1 km/h=100,000 cm/3600 s=27.7778 cm/s

So, in CGS units, 1 kilometer per hour is approximately equal to 27.7778 centimeters per second.

Examples of Kilometer Per Hour

  1. Usain Bolt’s world record sprint speed: 44.72 km/h
  2. Speed limit in many residential areas: 30 km/h
  3. Average running speed of a fit human: 8-16 km/h
  4. Speed of a typical car on a highway: 100 km/h
  5. Speed of the fastest land animal, the cheetah: 96-120 km/h
  6. Speed of a commercial passenger train: 160-320 km/h
  7. Typical cruising speed of a commercial airliner: 800 km/h
  8. Speed of a fast-moving storm: 50-80 km/h
  9. Maximum speed of some high-speed trains: 300-400 km/h
  10. Speed of a Category 5 hurricane: 250-280 km/h

Types of Kilometer Per Hour


Average Speed

  • Definition: The average number of kilometers traveled per hour over a given period of time, accounting for all stops and changes in speed.
  • Use: Often used to estimate travel times over long distances or in traffic studies to assess road usage patterns.

Instantaneous Speed

  • Definition: The speed of an object at a specific moment in time.
  • Use: Commonly displayed on vehicle speedometers, this measurement is crucial for ensuring compliance with speed limits and for safe driving.

Maximum Speed

  • Definition: The highest speed reached by a vehicle or object over a given distance or during a particular journey.
  • Use: Important in performance testing for vehicles, safety evaluations, and in sports analytics, especially in racing.

Cruise Speed

  • Definition: A comfortably sustainable speed for a vehicle over a long distance.
  • Use: Often referred to in terms of fuel efficiency assessments and optimal travel speed for long-distance trips in vehicles, especially airplanes and ships.
  • Definition: The maximum or minimum speed limit that vehicles are legally allowed to travel at on a particular road or zone.
  • Use: Essential for legal and safety regulations, enforced by traffic laws to prevent accidents and improve road safety.


Is Kilometer Per Hour the same as kilometers per hour?

Yes, “kilometer per hour” and “kilometers per hour” refer to the same unit of speed. The term can be used in both singular and plural forms depending on the context in which it is mentioned.

Why is Kilometer Per Hour important?

Kilometer per hour is important for ensuring compliance with road safety regulations, which are set to prevent accidents and improve traffic flow. It’s also used in various fields such as meteorology (to report wind speeds), sports (to measure athlete performance), and many areas of physics and engineering.

Kilometer Per Hour calculator

A kilometer per hour calculator computes speed by dividing the distance traveled in kilometers by the time taken in hours, providing results in km/h for efficient speed analysis.

Kilometer Per Hour in km h

Kilometer per hour (km/h) is a speed unit indicating the distance in kilometers an object travels within one hour, widely used for measuring vehicle speeds and setting speed limits.

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