How to Use the Wind Speed Converter
Enter a wind speed in whichever unit you have — mph, m/s, km/h, or knots — and this tool instantly converts it to all the others, plus the international Beaufort wind force scale. It's handy for checking weather alerts, planning outdoor activities, or making sense of marine and aviation forecasts.
The Beaufort scale was devised in 1805 by British naval officer Francis Beaufort. It rates wind strength from 0 (calm) to 12 (hurricane force) across 13 levels, originally based on how sails and sea conditions responded to the wind. Today each level maps to a standardized wind speed range in m/s.
Different fields favor different units: US weather reports and everyday conversation use mph, most of the rest of the world uses km/h, and mariners and pilots use knots because they align directly with nautical charts. Around Beaufort 4-5 (roughly 13-24 mph) small branches start moving noticeably, and by Beaufort 6 (roughly 25-31 mph) umbrellas become hard to use outdoors.
Frequently Asked Questions
The Beaufort scale is an international standard that rates wind strength from 0 (calm) to 12 (hurricane force) across 13 levels, originally based on observable effects like sea state and swaying trees.
A knot equals one nautical mile (1.15 mph) per hour, and it ties directly to nautical charts, which are laid out in minutes of latitude. That makes knots the standard for marine and aviation navigation.