Kilometers per Hour to Kilometers per Second Converter
Enter the speed in kilometers per hour below to convert it to kilometers per second.
Convert Kilometers per Hour to Kilometers per Second
Enter a value in kilometers per hour (km/h) to convert to kilometers per second (km/s).
Kilometers per Hour to Kilometers per Second Conversion Table
Table showing various kilometers per hour measurements converted to kilometers per second. Click any preset value or arrow to load it into the converter.
| Kilometers per Hour (km/h) | Kilometers per Second (km/s) |
|---|---|
| 1 km/h | 0.000277778 km/s |
| 2 km/h | 0.000555556 km/s |
| 2.5 km/h | 0.000694444 km/s |
| 5 km/h | 0.0013889 km/s |
| 10 km/h | 0.0027778 km/s |
| 15 km/h | 0.0041667 km/s |
| 20 km/h | 0.0055556 km/s |
| 25 km/h | 0.0069444 km/s |
| 30 km/h | 0.0083333 km/s |
| 50 km/h | 0.0138889 km/s |
How to Convert Kilometers per Hour to Kilometers per Second
To convert kilometers per hour to kilometers per second, multiply the speed by the following conversion ratio: 0.000277778 kilometers per second/kilometers per hour.
Since one kilometers per hour is equal to 0.000277778 kilometers per second, you can use this simple formula to convert:
The speed in kilometers per second is equal to the speed in kilometers per hour multiplied by 0.000277778.
For example, here's how to convert 5 kilometers per hour to kilometers per second using the formula above.
How Many Kilometers per Second Are in a Kilometers per Hour?
There are 0.000277778 kilometers per second in a kilometers per hour, which is why we use this value in the formula above.
Our kilometers per hour to kilometers per second calculator automatically converts your speed measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Kilometers per Hour and kilometers per second are both units used to measure speed. Keep reading to learn more about each unit.
What Is a Kilometers per Hour?
A kilometers per hour is a unit of speed equal to 0.2777778 meters per second (m/s), the base unit for speed. Standard metric road speed unit (1 m/s = 3.6 km/h). [1]
The kilometers per hour is classified as a metric and SI-compatible unit of speed. Kilometers per Hour can be abbreviated as km/h; for example, 1 kilometers per hour can be written as 1 km/h.
In the metric system, "kilo" is the standard SI prefix for thousands, or 10³. This makes the kilometers per hour (km/h) a convenient decimal multiple of the meters per second (m/s).
In practice, kilometers per hour (km/h) are widely used across standard speed applications within SI metric workflows, engineering documentation, and technical data sheets.
What Is a Kilometers per Second?
A kilometers per second is a unit of speed equal to 1,000 meters per second (m/s), the base unit for speed. Astrophysics & orbital velocity unit equal to 1,000 m/s. [2]
The kilometers per second is classified as an International System of Units (SI) unit of speed. Kilometers per Second can be abbreviated as km/s; for example, 1 kilometers per second can be written as 1 km/s.
In the metric system, "kilo" is the standard SI prefix for thousands, or 10³. This makes the kilometers per second (km/s) a convenient decimal multiple of the meters per second (m/s).
In practice, kilometers per second (km/s) are widely used across large-scale industrial, bulk, and macro-level speed specifications within International System of Units (SI) workflows, engineering documentation, and technical data sheets.
When converting speed between kilometers per hour (km/h) and kilometers per second (km/s), keep full floating-point precision (1 km/h = 0.000277778 km/s; 1 km/s = 3,600 km/h) during intermediate calculations and round only the final kilometers per second figure to match your instrument tolerance.
More Kilometers per Hour & Kilometers per Second Conversions
Need to calculate in the opposite direction? Use our kilometers per second to kilometers per hour calculator to switch your starting unit immediately. You can also explore related tools such as converting kilometers per second to kilometers per hour, converting kilometers per hour to miles per hour, or converting kilometers per hour to meters per second.
Convert from Kilometers per Hour
Frequently Asked Questions
References
- [1]NIST SP 811 StandardNIST SP 811 (NIST SP 811 App. B.9 (Velocity))·Speed Metrology Standard — Kilometers per Hour (km/h) to Kilometers per Second (km/s)
- [2]NIST OWM SpecificationNIST OWM (SI Units — Length & Distance)·Unit Specifications: Kilometers per Hour (km/h) & Kilometers per Second (km/s)
- [3]NIST CUU ReferenceNIST CUU (SI Coherent Derived Units (m/s))·Conversion Factors & Mathematical Basis (km/h to km/s)