Wind Speed Converter – Knots, mph, km/h, m/s & Beaufort in 3 Easy Steps
Wind Speed Converter
Use this wind speed converter to convert wind velocities across Knots, mph, km/h, m/s, and the Beaufort scale simultaneously.
Use this free wind speed converter to switch between knots, miles per hour (mph), kilometres per hour (km/h), metres per second (m/s) and the Beaufort scale all at once. Type a value in any box and the other four update, with a Beaufort reference table that describes each force from calm to hurricane.
Quick answer
1 knot = 1.852 km/h = 1.15078 mph = 0.51444 m/s. To convert knots to mph, multiply by 1.15078; knots to km/h, multiply by 1.852; km/h to m/s, divide by 3.6. For example, 25 knots = 28.77 mph = 46.3 km/h = 12.86 m/s, which is force 6 (strong breeze) on the Beaufort scale.
Table of Contents
Sailors and pilots talk in knots, weather apps in mph or km/h, engineers in metres per second, and marine forecasts in Beaufort force numbers. When you plan a sail, a flight, a drone shoot or an outdoor event, you often need all of them at once.
This wind speed converter shows every unit side by side and runs in your browser.
Wind Speed Units Explained
- Knot (kt): one nautical mile per hour, used at sea and in aviation.
- Miles per hour (mph): common in US and UK weather reports.
- Kilometres per hour (km/h): used in most other countries’ forecasts.
- Metres per second (m/s): the SI unit, used in science, engineering and some European forecasts.
- Beaufort scale: a 0 to 12 force scale that links wind speed to what you see on land and sea.
Wind Speed Conversion Formulas
- Knots to mph: mph = kt × 1.15078
- Knots to km/h: km/h = kt × 1.852
- Knots to m/s: m/s = kt × 0.51444
- km/h to m/s: m/s = km/h ÷ 3.6
- Beaufort from m/s: v = 0.836 × B3/2, the empirical formula used by meteorologists
Beaufort Scale Table
| Force | Description | Knots | km/h | Effects at sea |
|---|---|---|---|---|
| 0 | Calm | < 1 | < 2 | Sea like a mirror |
| 1 | Light air | 1 to 3 | 2 to 5 | Ripples |
| 2 | Light breeze | 4 to 6 | 6 to 11 | Small wavelets |
| 3 | Gentle breeze | 7 to 10 | 12 to 19 | Large wavelets, scattered whitecaps |
| 4 | Moderate breeze | 11 to 16 | 20 to 28 | Small waves, frequent whitecaps |
| 5 | Fresh breeze | 17 to 21 | 29 to 38 | Moderate waves, many whitecaps |
| 6 | Strong breeze | 22 to 27 | 39 to 49 | Large waves, spray |
| 7 | Near gale | 28 to 33 | 50 to 61 | Sea heaps up, foam streaks |
| 8 | Gale | 34 to 40 | 62 to 74 | Moderately high waves |
| 9 | Strong gale | 41 to 47 | 75 to 88 | High waves, dense foam |
| 10 | Storm | 48 to 55 | 89 to 102 | Very high waves |
| 11 | Violent storm | 56 to 63 | 103 to 117 | Exceptionally high waves |
| 12 | Hurricane force | 64+ | 118+ | Air filled with foam and spray |
How to Use the Wind Speed Converter
Step 1: Enter a Wind Speed in Any Unit
Type a value into any field. Entering 25 knots shows 28.77 mph, 46.3 km/h, 12.86 m/s and Beaufort force 6. Use the copy buttons to grab any value.
Step 2: Convert km/h to Beaufort Force
Start from the unit in your forecast. 100 km/h converts to 54 knots, 62.14 mph and 27.78 m/s, which is force 10, a storm on the Beaufort scale.
Step 3: Read the Beaufort Reference
The quick reference table below the fields lists every force from 0 (calm) to 12 (hurricane) with its knot range, so you can see what conditions to expect.
Wind Speed Guides for Activities
- Small boat sailing: many beginners prefer force 2 to 4 (4 to 16 knots).
- Kitesurfing and windsurfing: commonly 12 to 25 knots depending on board and kite size.
- Drones: many consumer drones list a maximum wind resistance around 10 to 12 m/s; check your model.
- Cycling and running: headwinds above about 20 mph (32 km/h) noticeably slow you down.
- Outdoor events: tents and stages often have wind limits in m/s or mph in the supplier’s manual.
These are general guides. Always follow local forecasts, equipment limits and safety rules.
Need other conversions? Try the Volumetric Flow Rate Converter for air flow or the Gas Pressure Converter for pressure.
Frequently Asked Questions
How do I convert knots to mph?
Multiply knots by 1.15078. For example, 20 knots is about 23 mph.
How fast is 1 knot in km/h?
Exactly 1.852 km/h, because one nautical mile is 1,852 metres.
What Beaufort force is 30 knots?
30 knots is force 7, a near gale.
How do I convert km/h to m/s?
Divide by 3.6. For example, 36 km/h is 10 m/s.
Why do sailors use knots?
Knots are based on nautical miles, which relate directly to latitude on charts, making navigation easier.
Is my data saved?
No. The wind speed converter runs entirely in your browser.