100 km/h to m/s
- Kilometers per hour (km/h)
- 100 km/h
- Meters per second
- 27.7777777778 m/s
Checked against: Exact-fraction computation from the legal unit definitions
Kilometers per hour to meters per second converter
Convert kilometers per hour to meters per second (km/h to m/s) with the exact factor, a conversion chart and worked steps.
By AdminDrafted with AI writing toolsUpdated Checked examples: 3
Meters per second
m/s
Meters per second: 27.7777777778 m/s
- Conversion
- 100 km/h = 27.7777777778 m/s
- 1 m/s in kilometers per hour
- 3.6km/h
100 km/h is about 27.7777777778 m/s. In the other direction, 1 m/s ≈ 3.6 km/h.
Kilometers per hour to meters per second
Km/h to m/s chart
| Kilometers per hour | Meters per second |
|---|---|
| 1 | 0.2778 |
| 10 | 2.7778 |
| 20 | 5.5556 |
| 30 | 8.3333 |
| 50 | 13.8889 |
| 60 | 16.6667 |
| 80 | 22.2222 |
| 100 | 27.7778 |
| 120 | 33.3333 |
| 300 | 83.3333 |
How it's calculated S
Conversion factor
Rounded here for display; the calculation uses 50 significant digits.
Multiply
About the kilometers per hour to meters per second converter
To convert kilometers per hour to meters per second, multiply by 0.2777777778; to convert back, multiply by 3.6. For example, 100 km/h is about 27.777778 m/s. Displayed factors and results may be rounded.
A kilometer-per-hour reading combines a metric distance with an hour. Converting it is useful for a vehicle comparison or a physics problem expressed in seconds. Keep instantaneous speed separate from a whole-trip average that includes stops.
kilometre per hour: 1 km/h = 1,000 m / 3,600 s; 1 m/s = 3.6 km/h. These values are exact.
Both units are defined exactly. Calculations use 50 significant digits and round only for display.
How to convert km/h to m/s
Divide kilometers per hour by 3.6: m/s = km/h ÷ 3.6. So 36 km/h is exactly 10 m/s, 90 km/h is 25 m/s and 100 km/h is 27.78 m/s. Use it whenever a physics formula, a lab report or a stopping-distance estimate needs speed per second.
The 5/18 shortcut
A kilometer per hour is 1,000 m per 3,600 s, so dividing by 3.6 is the same as multiplying by 5/18 (NIST SP 811, Appendix B).
Multiples of 18 come out whole: 18 km/h is 5 m/s, 54 km/h is 15 m/s, 72 km/h is 20 m/s and 108 km/h is 30 m/s.
km/h to m/s chart
| Kilometers per hour | Meters per second, rounded |
|---|---|
| 10 | 2.777778 |
| 30 | 8.333333 |
| 36 | 10.000000 |
| 50 | 13.888889 |
| 72 | 20.000000 |
| 100 | 27.777778 |
How far a car travels each second
Meters per second show how much road passes while a driver reacts. At 50 km/h a car covers 13.89 m every second, so a 1.5-second reaction uses about 20.8 m before braking starts. At 100 km/h the same pause takes 41.7 m.
The same arithmetic works for any steady speed: at 36 km/h, which is 10 m/s, 10 seconds covers 100 m.
Physics formulas need m/s
Kinetic energy, ½mv², gives joules only when v is in m/s. A 1,500 kg car at 100 km/h moves at 27.78 m/s and carries about 579 kJ.
Plugging in 100 gives 7.5 MJ instead, 12.96 times too much, because the speed error of 3.6 is squared. The kinetic energy calculator keeps the units straight.
Common mistakes
- Multiplying by 3.6. That converts m/s to km/h and turns 100 km/h into 360. The m/s figure is always the smaller one.
- Rounding the factor to 0.28. 100 × 0.28 = 28 m/s, 0.8% high. Dividing by 3.6 or multiplying by 5/18 is exact.
- Converting mph with 3.6. Miles per hour need their own factor: 1 mph is exactly 0.44704 m/s.
Related speed conversions
The m/s to km/h converter goes the other way, km/h to mph gives road speeds in miles, and the speed converter adds knots and feet per second.
Worked examples
30 km/h to m/s
- Kilometers per hour (km/h)
- 30 km/h
- Meters per second
- 8.3333333333 m/s
Checked against: Exact-fraction computation from the legal unit definitions
120 km/h to m/s
- Kilometers per hour (km/h)
- 120 km/h
- Meters per second
- 33.3333333333 m/s
Checked against: Exact-fraction computation from the legal unit definitions
Questions
How many meters per second is one kilometer per hour?
1 km/h is about 0.2777777778 m/s. kilometre per hour: 1 km/h = 1,000 m / 3,600 s; 1 m/s = 3.6 km/h. These values are exact.
How do I convert kilometers per hour to meters per second?
Multiply by 0.2777777778: 100 km/h × 0.2777777778 ≈ 27.777778 m/s. To convert back, divide by the same factor. The factor shown may be rounded.
How can I estimate kilometers per hour in meters per second without a calculator?
Multiply by 0.28. This is 0.8% above the exact factor (about 0.2777777778), so 100 km/h comes out as 28 m/s instead of 27.7778 m/s.
About this calculator
Sources
Checked against references
This calculator includes 3 worked examples with independently sourced answers. They run in the test suite, and you can run them here too.