Speed Converter
Result
3.6 Kilometer/Hour
How these units are defined
Speed units are a length divided by a time: 1 km/h = 1/3.6 m/s, 1 mph = 0.44704 m/s exactly, and 1 knot = 1 nautical mile per hour = 1,852/3,600 m/s.
| Unit | Equals |
|---|---|
| 1 Kilometer/Hour | 0.2777777778 Meter/Second |
| 1 Mile/Hour | 0.44704 Meter/Second |
| 1 Knot | 0.5144444444 Meter/Second |
| 1 Foot/Second | 0.3048 Meter/Second |
Worked examples
- 30 Kilometer/Hour = 18.641136 Mile/Hour
- 50 Kilometer/Hour = 31.06856 Mile/Hour
- 100 Kilometer/Hour = 62.137119 Mile/Hour
- 120 Kilometer/Hour = 74.564543 Mile/Hour
Common mistakes
- A knot is a nautical mile per hour, so 1 kn = 1.852 km/h and 1.15078 mph — not 1 mph.
- Weather services quote wind in km/h, m/s, mph or knots depending on country; check the unit before comparing forecasts.
Speed conversions
Frequently asked questions
How do I convert km/h to mph?
To convert kilometers per hour to miles per hour, multiply by 0.621371. For example, 100 km/h = 62.14 mph.
What is a knot in speed terms?
A knot is one nautical mile per hour, equal to approximately 1.852 km/h or 1.151 mph. It is used in maritime and aviation navigation.
How fast is Mach 1?
Mach 1 is the speed of sound, approximately 1,235 km/h (767 mph) at sea level and 20°C. It varies with temperature and altitude.
Sources for these factors
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
- Handbook 44 (2024), Appendix C: General Tables of Units of Measurement — NIST
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy