Weather converter
Wind Speed Converter
How the wind speed converter works
Enter a wind speed in any field and the others update instantly. Forecasts in the US use mph, most of the world uses km/h, sailors and aviators use knots, and scientists use meters per second - this tool speaks all of them.
1 mph = 1.609 km/h 1 knot = 1.151 mph 1 m/s = 2.237 mphQuick tips
- Quick mental math: knots to mph, add half again minus a bit (20 kn ≈ 23 mph); mph to km/h, multiply by 1.6.
- Gusts vs. sustained wind: forecasts quote sustained wind; gusts typically run 30-40% higher.
- Anchor the scale: 10 mph moves leaves, 30 mph moves whole trees, 60 mph moves roof shingles.
Wind speed conversion chart
| mph | km/h | kn | m/s | ft/s |
|---|---|---|---|---|
| 1 | 1.61 | 0.87 | 0.45 | 1.47 |
| 5 | 8.05 | 4.34 | 2.24 | 7.33 |
| 10 | 16.09 | 8.69 | 4.47 | 14.67 |
| 15 | 24.14 | 13.03 | 6.71 | 22 |
| 20 | 32.19 | 17.38 | 8.94 | 29.33 |
| 25 | 40.23 | 21.72 | 11.18 | 36.67 |
| 30 | 48.28 | 26.07 | 13.41 | 44 |
| 40 | 64.37 | 34.76 | 17.88 | 58.67 |
| 50 | 80.47 | 43.45 | 22.35 | 73.33 |
| 60 | 96.56 | 52.14 | 26.82 | 88 |
| 74 | 119.09 | 64.3 | 33.08 | 108.53 |
| 100 | 160.93 | 86.9 | 44.7 | 146.67 |
| 150 | 241.4 | 130.35 | 67.06 | 220 |
Beaufort wind scale
| Force | Name | Wind speed | Effects on land |
|---|---|---|---|
| 0 | Calm | < 1 mph | Smoke rises vertically |
| 1 | Light air | 1-3 mph | Smoke drifts, vanes still |
| 2 | Light breeze | 4-7 mph | Leaves rustle, wind felt on face |
| 3 | Gentle breeze | 8-12 mph | Leaves and small twigs in motion |
| 4 | Moderate breeze | 13-18 mph | Dust and loose paper lift |
| 5 | Fresh breeze | 19-24 mph | Small trees sway |
| 6 | Strong breeze | 25-31 mph | Large branches move, umbrellas struggle |
| 7 | Near gale | 32-38 mph | Whole trees in motion |
| 8 | Gale | 39-46 mph | Twigs break off, walking is hard |
| 9 | Strong gale | 47-54 mph | Minor structural damage |
| 10 | Storm | 55-63 mph | Trees uprooted, considerable damage |
| 11 | Violent storm | 64-72 mph | Widespread damage |
| 12 | Hurricane force | 73+ mph | Devastation; hurricane categories begin |
Frequently asked questions
How fast is a knot compared to mph?
One knot is one nautical mile per hour, which equals 1.151 mph or 1.852 km/h. A 20-knot wind is about 23 mph.
What wind speed is dangerous?
Sustained winds around 40 mph (64 km/h) make walking difficult and break twigs; 58+ mph (93 km/h) triggers severe-thunderstorm warnings in the US; hurricane force starts at 74 mph (119 km/h).
Why do meteorologists use knots?
Weather observations follow marine and aviation conventions, where distances are in nautical miles. Public forecasts translate to mph or km/h.