Windsock Calculator
Estimate how far a windsock will stream horizontally based on wind speed. Great for quick field checks, airport ops, or drone pilots.
Enter the wind speed at which the windsock is fully horizontal.
Helps estimate how many stripes should inflate based on wind speed.
Windsock Angle
48.0°
0.84 radians
Wind Speed Conversion
9.2 mph
14.8 km/h
4.1 m/s
Visual Estimate
3 stripe(s) inflated
Beaufort: Gentle breeze
How to Use This Calculator
Measure the wind speed
Grab the latest METAR, handheld anemometer, or forecast value in knots. Knots are standard for aviation.
Know your windsock rating
Most FAA-compliant windsocks extend horizontally at 15 knots. Adjust the full-fly speed if your windsock differs.
Optionally enter stripe count
Many windsocks use 5 stripes. Enter the count to estimate how many will inflate at the current wind speed.
Formula
Windsock Angle = min(1, Wind Speed ÷ Full Extension Speed) × 90°
Angle interpretation: 0° = hanging straight down, 90° = fully horizontal.
Stripe estimate: Inflated stripes ≈ Total Stripes × (Wind Speed ÷ Full Extension Speed).
Example: Wind 8 kt, full-fly 15 kt, 5 stripes → Angle = 8 ÷ 15 × 90° ≈ 48° → Stripes = 5 × 8 ÷ 15 ≈ 3 stripes inflated.
About the Windsock Calculator
Windsocks provide quick visual cues to wind strength and direction. This calculator converts measured wind speed into an approximate windsock angle to help pilots and crews interpret conditions when the windsock isn’t in view.
When to Use This Calculator
- Aviation ops: Estimate windsock behavior from forecast wind speeds.
- Helipads / hospitals: Ensure windsocks meet visibility requirements under expected winds.
- Drone pilots: Visualize whether wind exceeds operational limits.
- Industrial sites: Train staff to interpret windsock deflection for evacuation planning.
Why Use Our Calculator?
- ✅ Simple model: Converts wind speed to angle with a linear relationship based on rated windsock speed.
- ✅ Multi-unit output: Automatically shows mph, km/h, and m/s.
- ✅ Visual cues: Stripe estimate helps cross-check when viewing the windsock remotely.
- ✅ Free & mobile-friendly: Check conditions from the ramp or cockpit.
Common Applications
Airport managers: Verify windsock specifications against typical wind conditions.
Pilots: Anticipate windsock behavior on approach or before pattern entry.
Safety officers: Train crews on how windsock deflection correlates with measured wind speed.
Tips for Best Results
- Check the manufacturer’s rated wind speed for full deflection—many are 12 or 15 knots.
- Windsocks react to gusts and steady winds differently; use averaged wind speeds for planning.
- Humidity and fabric wear can affect droop—inspect and replace windsocks periodically.
- Install windsocks clear of turbulence to ensure reliable readings.
Frequently Asked Questions
Are windsock angles perfectly linear with wind speed?
Real windsocks behave close to linear up to their rated speed, but fabric stiffness, wear, and gusting winds introduce small deviations. This calculator provides an approximation.
What if my windsock is calibrated in mph?
Convert mph to knots (mph × 0.868976). Or adjust the full extension speed input using the equivalent knotted value.
How accurate is the stripe estimate?
Most FAA windsocks have five stripes, each representing roughly an equal increment. The estimate assumes uniform stripe lengths; treat it as a guideline.
Can I use this for large IFR windsocks?
Yes. Just enter the correct full extension speed from the windsock specification. Larger windsocks often require 15 knots to fly horizontally.