## Definitions

### Kilometers per hour

Kilometer per hour is a unit of speed that measures the number of kilometers an object travels within an hour. Kilometer is defined as one thousand meters, the base length unit in SI system of units. Typically, kilometer per hour is denoted as a ratio km/h. However, it also appears as an abbreviation (kmph, kph), particularly on labels or road signs.

The relationships of km/h to other speed units are shown in the following table:

Unit | Symbol | [km/h] |
---|---|---|

Nanometer per second | nm/s | \(3.6 \cdot 10^{-9}\) |

Micrometer per second | μm/s | \(3.6\cdot 10^{-6}\) |

Millimeter per second | mm/s | \(0.0036\) |

Centimeter per second | cm/s | \(0.036\) |

Meter per second | m/s | \(3.6\) |

Kilometer per second | km/s | \(3600\) |

Megameter per second | Mm/s | \(3.6\cdot10^6\) |

Gigameter per second | Gm/s | \(3.6\cdot10^9\) |

Mile per hour | mph | \(1.609344\) |

Foot per second | ft/s | \(1.09728\) |

### Meters per second

Meters per second [m/s] is a unit of speed according to the SI system of units. It measures the number of meters an object travels within a second. Meter [m] is the base unit of length in SI system. It was originally conceived as 1/10,000,000 of the distance along earth's meridian, from the equator to the North Pole. Today, it is defined as the distance traveled by light in vacuum in \(\frac{1}{299\,792\,458}\) seconds.

The relationship of meter per second [m/s] with other speed units are shown in the following table:

Unit | Symbol | [m/s] |
---|---|---|

Nanometer per second | nm/s | \( 10^{-9}\) |

Micrometer per second | μm/s | \(10^{-6}\) |

Millimeter per second | mm/s | \(0.001\) |

Centimeter per second | cm/s | \(0.01\) |

Kilometer per second | km/s | \(1000\) |

Megameter per second | Mm/s | \(10^6\) |

Gigameter per second | Gm/s | \(10^9\) |

Meter per hour | m/h | \(\frac{1}{3600}\) |

Kilometer per hour | km/h | \(\frac{1}{3.6}\approx 0.277778\) |

Mile per hour | mph | \(0.44704\) |

Foot per second | ft/s | \(0.3048\) |

### How to convert meters per second to kilometers per hour (m/s to km/h)

- Multiply speed in m/s with 3600
- Divide the results by 1000
- The result is the speed in kilometers per hour

For example 25m/s is 25x3600/1000 = 90 km/h

### How to convert kilometers per hour to meters per second (km/h to m/s)

- Multiply speed in km/h with 1000
- Divide the result by 3600
- The result is the speed in m/s

For example 120 km/h is 120x1000/3600 ≈ 33.333 m/s

### Conversion table from [m/s] to [km/h]

In the following table some typical speeds in meters per second are converted to kilometers per hour:

[m/s] | [km/h] |
---|---|

1 | |

2 | |

5 | |

10 | |

15 | |

20 | |

25 | |

30 | |

35 | |

40 | |

45 | |

50 | |

55 | |

60 | |

65 | |

70 | |

80 | |

90 | |

100 | |

150 | |

200 |

### Conversion table from [km/h] to [m/s]

In the following table some typical speeds in kilometers per hour are converted to meters per second:

[mph] | [km/h] |
---|---|

1 | |

2 | |

5 | |

10 | |

15 | |

20 | |

25 | |

30 | |

35 | |

40 | |

45 | |

50 | |

55 | |

60 | |

65 | |

70 | |

80 | |

90 | |

100 | |

150 | |

200 |