kilometer per hour to millimeter per second
Convert kilometer per hour (km/h) to millimeter per second (mm/s). Use an editable speed converter, conversion formula, and reference table.
1 km/h = 277.7777778 mm/s
Conversion formula
One kilometer per hour equals 277.7777778 millimeter per second. Multiply your value in kilometer per hour by this factor to get millimeter per second. For the reverse conversion, divide by the same factor.
Worked example
To convert 5 kilometer per hour:5 × 277.7777778 = 1,388.888889 mm/s
Conversion table
| kilometer per hour (km/h) | millimeter per second (mm/s) |
|---|---|
| 0.01 | 2.777777778 |
| 0.1 | 27.77777778 |
| 1 | 277.7777778 |
| 2 | 555.5555556 |
| 5 | 1,388.888889 |
| 10 | 2,777.777778 |
| 25 | 6,944.444444 |
| 50 | 13,888.88889 |
| 100 | 27,777.77778 |
| 1000 | 277,777.7778 |
About these measurements
Speed is distance traveled per unit of time.
The base reference used here is the meter per second. One kilometer per hour is 0.2777777778 base units; one millimeter per second is 0.001 base units.
Important distinctions
Mach is excluded because the speed of sound depends on medium and temperature.
Precision
The converter uses stored conversion factors and floating-point arithmetic. Results display up to ten significant digits, switching to scientific notation for very small or large values. Keep the precision of your original measurement when reporting results.
Common questions
How do I convert km/h to mm/s?
Multiply the quantity in km/h by 277.7777778. You can also type the value into the converter above.
Can I reverse the conversion?
Yes. Use the swap button or open the millimeter per second to kilometer per hour converter.
Reference
NIST Guide to the SI — conversion factors and prefix conventions. SI prefixes scale units by powers of ten; the dimension-specific notes above describe the assumptions used on this page.
