Windsock Calculator: Read Wind Speed from a Windsock

Windsock Calculator

Read wind speed straight off a windsock

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A standard aviation windsock is built from 5 stacked segments. Wind pressure inflates the cone from the mounting end outward — the stronger the wind, the more segments stand horizontal instead of drooping.

Each fully horizontal segment represents roughly 3 knots of wind. A sock hanging limp means calm air (under 1–3 knots); all 5 segments standing straight out means 15 knots or more. You can also estimate from the droop angle of the sock below the horizontal.

How Are You Reading It?

Count Raised Segments Estimate Droop Angle

Raised Segments

Count how many of the sock's 5 tapered segments are standing straight out from the mast.

Sock Size

Mounting height is typically 4.8 m (15.7 ft) above the ground on a rigid mast. This doesn't affect the speed reading — it's for reference only.

💨 Your Result

Estimated Wind Speed

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Fill in the fields above to calculate

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km/h

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mph

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m/s

Calculation

A windsock gives an immediate visual read of wind speed without any instruments, if you know how to interpret it, this calculator converts what you observe, either raised segments or droop angle, into an actual wind speed figure.

How to use this windsock calculator

Choose how you’re reading it: Count Raised Segments, or Estimate Droop Angle.
For segments, select how many of the sock’s 5 segments are standing horizontal.
For angle, enter the droop angle below horizontal in degrees.
Read the Estimated Wind Speed in km/h, mph, and m/s.

What this calculator does

A standard aviation windsock is built from 5 stacked, tapered segments. Wind pressure inflates the cone from the mounting end outward, the stronger the wind, the more segments stand fully horizontal instead of drooping. Each fully horizontal segment represents roughly 3 knots of wind, so a sock hanging limp indicates calm air (under 1 to 3 knots), while all 5 segments standing straight out indicates 15 knots or more.

Estimated Wind Speed (knots) ≈ Raised Segments × 3

Reading by droop angle instead of segment count

The alternative method estimates wind speed from the angle the sock droops below horizontal: 0° means the sock is flat and horizontal (fully extended, indicating high wind), while 90° means it’s hanging straight down (calm, no wind). This method can offer finer resolution than the 5-segment count when the wind speed falls between two segment thresholds.

Why windsocks are standardized

A standard aviation windsock measures 3.60 m long with a 0.90 m diameter, while a compact version measures 2.50 m long with a 0.45 m diameter. Mounting height is typically 4.8 m (15.7 ft) above the ground on a rigid mast, this standardization is why segment-count readings translate consistently to a wind speed estimate across different airfields, though the sock size and mounting height are shown here for reference only and don’t affect the speed reading itself.

Frequently asked questions

How many knots does each raised windsock segment represent?

Roughly 3 knots per fully horizontal segment, a sock hanging limp indicates calm air under 1 to 3 knots, while all 5 segments standing straight out indicates wind of 15 knots or more.

What does a 0-degree droop angle mean?

It means the windsock is completely flat and horizontal, indicating high wind (fully extended). A 90-degree droop angle means the sock is hanging straight down, indicating calm, essentially windless conditions.

Does windsock size or mounting height affect the wind speed reading?

No, the standard dimensions and typical 4.8 m mounting height are shown for reference only, the actual wind speed reading comes purely from how many segments are raised or the droop angle observed, independent of the sock’s specific size.