Menu
Speed converter

kilometer per hour to mile per second

Convert kilometer per hour (km/h) to mile per second (mi/s). Use an editable speed converter, conversion formula, and reference table.

0.000172603109

1 km/h = 0.000172603109 mi/s

Calculated in your browser

Conversion formula

mi/s = km/h × 0.000172603109

One kilometer per hour equals 0.000172603109 mile per second. Multiply your value in kilometer per hour by this factor to get mile per second. For the reverse conversion, divide by the same factor.

Worked example

To convert 5 kilometer per hour:
5 × 0.000172603109 = 0.0008630155448 mi/s

Conversion table

kilometer per hour (km/h)mile per second (mi/s)
0.010.00000172603109
0.10.0000172603109
10.000172603109
20.0003452062179
50.0008630155448
100.00172603109
250.004315077724
500.008630155448
1000.0172603109
10000.172603109

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 mile per second is 1,609.344 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 mi/s?

Multiply the quantity in km/h by 0.000172603109. You can also type the value into the converter above.

Can I reverse the conversion?

Yes. Use the swap button or open the mile 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.

More tools and guidance

Find the next calculation
you need.

Browse calculatorsFind your industry
Cobalt ribbon, chrome ring and orange sphere in architectural light

Search AskToBot

Start typing to find a calculator or conversion.