Instantly convert between miles per hour (mph), kilometres per hour (km/h), knots (kn), and metres per second (m/s) using official conversion factors. Perfect for driving, aviation, boating, cycling, motorsports, engineering and scientific calculations.
✔ mph ⇄ km/h • ✔ Knots & m/s • ✔ Instant conversion • ✔ Free converter
The Speed Converter quickly converts between the world's four most commonly used speed units: miles per hour (mph), kilometres per hour (km/h), knots (kn), and metres per second (m/s). It uses official international conversion factors to provide fast, accurate, and reliable results.
Whether you're driving, travelling, flying, sailing, cycling, studying physics, or comparing vehicle specifications, this converter makes switching between speed units simple.
km/h = mph × 1.60934
mph = km/h ÷ 1.60934
m/s = km/h ÷ 3.6
kn = km/h ÷ 1.852
km/h = kn × 1.852
kn = mph × 0.86898
| mph | km/h | Knots | m/s |
|---|---|---|---|
| 10 | 16.09 | 8.69 | 4.47 |
| 20 | 32.19 | 17.38 | 8.94 |
| 30 | 48.28 | 26.08 | 13.41 |
| 40 | 64.37 | 34.76 | 17.88 |
| 50 | 80.47 | 43.45 | 22.35 |
| 60 | 96.56 | 52.14 | 26.82 |
| 70 | 112.65 | 60.83 | 31.29 |
| 100 | 160.93 | 86.90 | 44.70 |
Road vehicles use mph in the UK and US, while most countries use km/h.
Compare vehicle performance and top speeds across different countries.
Aircraft and ships commonly measure speed in knots.
Metres per second (m/s) is the SI standard unit for speed.
| Object | mph | km/h |
|---|---|---|
| Walking | 3 | 5 |
| Running | 10 | 16 |
| Cyclist | 15 | 24 |
| UK Motorway | 70 | 113 |
| High-speed Train | 186 | 300 |
| Formula 1 Car | 220 | 354 |
| Commercial Jet | 575 | 925 |
This converter performs every calculation automatically using internationally recognised conversion factors, helping you avoid conversion errors.
What is a knot?
A knot is one nautical mile per hour and is the standard speed unit used in aviation and marine navigation.
Which countries use mph?
The United Kingdom, United States and a small number of other countries primarily use miles per hour for road speed limits.
Which countries use km/h?
Most countries worldwide use kilometres per hour for road transport.
Why is m/s used in science?
Metres per second is the official SI (International System of Units) measurement for speed used in physics and engineering.
Can I convert between all four units?
Yes. This converter supports every conversion between mph, km/h, knots and metres per second.
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Last Updated: August 2026