How to Convert Metres per second to Kilometres per hour (m/s to km/h)
Speed conversions come up with expressway limits in km/h, foreign car specs in mph and wind speeds reported in knots by the Meteorological Service. This guide shows how to convert metres per second into kilometres per hour by hand, with examples and a quick-reference table.
The conversion
To convert metres per second to kilometres per hour, multiply the value by 3.6. To go the other way, divide by the same number (or multiply by 0.2777777778). For a quick estimate, multiply by about 3.6.
Kilometres per hour = metres per second × 3.6
Worked examples
- 3 m/s = 10.8 km/h
- 12.5 m/s = 45 km/h
- 75 m/s = 270 km/h
Metres per second to Kilometres per hour table
| Metres per second | Kilometres per hour |
|---|---|
| 1 m/s | 3.6 km/h |
| 2 m/s | 7.2 km/h |
| 5 m/s | 18 km/h |
| 10 m/s | 36 km/h |
| 20 m/s | 72 km/h |
| 25 m/s | 90 km/h |
| 50 m/s | 180 km/h |
| 100 m/s | 360 km/h |
| 250 m/s | 900 km/h |
| 500 m/s | 1,800 km/h |
| 1,000 m/s | 3,600 km/h |
Common questions
Is m/s to km/h exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Kilometres per hour to Metres per second converter.
Mistakes to avoid
Dropping the units
A bare number without a unit is easy to misread later. Always write the unit with the result.
Forgetting squared and cubed units
Area and volume factors are the length factor squared or cubed, so 1 m² is about 10.76 sq ft, not 3.28.
Rounding the factor too early
Using 3 instead of 3.28 for feet per metre introduces an error of almost 9% before you have started.
Background
Many conversion factors are exact by definition. The inch has been defined as exactly 2.54 centimetres since 1959, and the pound as exactly 0.45359237 kilograms, so conversions involving them can be as precise as you need.
For everyday use, three or four significant figures are usually enough. Engineering, science and trade documents may need more, and rounding should happen only at the end of a calculation.
Singapore adopted the metric system in the 1970s, replacing imperial units and traditional Chinese measures in most official uses. Metric units are now standard in schools, trade and government, but older units survive in property, markets and imported goods.
For any value, use the Metres per second to Kilometres per hour Converter or browse all speed converters.
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