Speed Converter
Convert speed units between m/s, km/h, mph, knots, ft/s, cm/s, and Mach number.
✓ Runs in your browser · Updated 2026-03-31Enter values and click Convert to see results
How Speed Conversion Works
All speed units convert through metres per second (m/s) as the base unit. Each unit has a factor that represents how many m/s it equals. For example, 1 km/h ≈ 0.27778 m/s, and Mach 1 ≈ 343 m/s (speed of sound at sea level, 20°C).
Speed Limits in India
| Road Type | Cars (km/h) | Trucks (km/h) |
|---|---|---|
| Expressways (e.g., Yamuna Expressway) | 120 | 80 |
| National Highways | 100 | 80 |
| State Highways | 80 | 65 |
| City Roads | 50–70 | 40–50 |
| Residential / School Zones | 25–30 | 25 |
Indian expressways like the Mumbai-Pune Expressway have a max speed of 80–100 km/h. The upcoming Delhi-Mumbai Expressway will allow 120 km/h for cars.
Understanding Mach Number
Mach number is the ratio of an object's speed to the speed of sound. Mach 1 ≈ 343 m/s or 1,235 km/h at sea level. Fighter jets like the Rafale (used by IAF) can reach Mach 1.8. Commercial aircraft cruise at about Mach 0.8 (860 km/h). Knots are standard in aviation and maritime — 1 knot = 1.852 km/h.
Related Converters
For distance calculations, use the Length Converter. For physics and energy comparisons, check the Energy Converter.
Frequently Asked Questions
How do I convert km/h to m/s?
Divide the speed in km/h by 3.6. For example, 90 km/h = 25 m/s.
How many km/h is 1 mph?
1 mile per hour (mph) is equal to approximately 1.609 km/h.
What is a knot in terms of km/h?
1 knot equals approximately 1.852 km/h. Knots are commonly used in aviation and maritime navigation.