Kilometer/Hour to Millimeter/Second Converter

Speed Converter

18 units available

Decimals:

From

To

277.777778

1 km/h = 277.777778 mm/s

Formula:

mm/s = km/h × 277.7777777778

With your value: 1 km/h = 277.77777778 mm/s

How big is that?

Everyday references on a logarithmic scale, all expressed in kilometer/hour so you can sanity-check the result.

Your value1.00 km/h

Walking pace (5.0× your value)5.04 km/h

Cycling (20× your value)19.8 km/h

Urban speed limit (50 km/h) (50× your value)50.0 km/h

Cheetah sprint (1.0e+2× your value)104 km/h

Motorway (110 km/h) (1.1e+2× your value)110 km/h

Other Kilometer/Hour to Millimeter/Second conversions

2 km/h to mm/s 3 km/h to mm/s 4 km/h to mm/s 5 km/h to mm/s 6 km/h to mm/s 7 km/h to mm/s 8 km/h to mm/s

Kilometer/Hour to Millimeter/Second Conversion Table

Kilometer/Hour (km/h)	Millimeter/Second (mm/s)
0.5	138.888889
1	277.777778
2	555.555556
5	1,388.888889
10	2,777.777778
15	4,166.666667
20	5,555.555556
25	6,944.444444
50	13,888.888889
100	27,777.777778
250	69,444.444444
500	138,888.888889
1000	277,777.777778

Millimeter/Second to Kilometer/Hour Conversion Table

Millimeter/Second (mm/s)	Kilometer/Hour (km/h)
0.5	0.0018
1	0.0036
2	0.0072
5	0.018
10	0.036
15	0.054
20	0.072
25	0.09
50	0.18
100	0.36
250	0.9
500	1.8
1000	3.6

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Kilometer/Hour (km/h)

Speed

Exact conversion

Derived quantity: a defined length divided by a defined time interval.

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

Millimeter/Second (mm/s)

Speed

Exact conversion

Derived quantity: a defined length divided by a defined time interval.

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

How to Convert Kilometer/Hour to Millimeter/Second

To convert from Kilometer/Hour (km/h) to Millimeter/Second (mm/s), multiply the value by 277.7777777778.

Formula: mm/s = km/h × 277.7777777778

Reverse: km/h = mm/s × 0.0036

Step-by-Step Example

Start with your value in Kilometer/Hour. For example: 5 km/h
Multiply by the conversion factor: 5 x 277.7777777778
The result is: 1,388.888889 mm/s

About Kilometer/Hour

Kilometers per hour is the most widely used unit of speed for vehicles in most countries.

Common uses: speed limits, vehicle speed, weather.

About Millimeter/Second

The millimeter/second (mm/s) is a unit of speed and velocity. One millimeter/second equals 0.001 metre per seconds. UnitConvertLab converts it against every other speed unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: speed calculations, engineering and science, education.

Frequently Asked Questions

How many Millimeter/Second are in 1 Kilometer/Hour?

There are exactly 277.7777777778 Millimeter/Second in 1 Kilometer/Hour. This means the conversion factor from Kilometer/Hour to Millimeter/Second is 277.7777777778.

What is the formula to convert Kilometer/Hour to Millimeter/Second?

The formula to convert Kilometer/Hour to Millimeter/Second is: mm/s = km/h × 277.7777777778. For example, to convert 10 Kilometer/Hour to Millimeter/Second, you would multiply 10 by 277.7777777778.

What is a Kilometer/Hour?