# Windsurfing Sail and Board Size Calculator

URL: https://speedycalculator.com/calculators/sports/windsurfing/
Last updated: 2026-10-30

> The windsurfing calculator recommends a sail size from your weight and the wind speed, and a board volume from your weight and skill level – from beginner boards to wave sinkers.

## Inputs

- Sailor weight (kg, lb)
- Wind speed (kn, km/h, mph, m/s)
- Your level

## Results

- Wind
- Recommended sail size
- Recommended board volume
- Typical fin length

## Formula

```
Sail (m²) = weight (kg) × 1.34 ÷ wind (knots) · Board volume (L) = weight (kg) + skill bonus (beginner +130, intermediate +100, first short board +60, … sinker 0 or less)
```

## Explanation

Windsurfing gear is sized to the rider and the conditions: heavier sailors need more sail and floating volume, while experienced riders use smaller boards that sink when stationary but are fast and agile when planing.

### How to use the Windsurfing Sail and Board Size Calculator

- **Sailor weight**
- **Wind speed**
- **Your level**

Rough guidelines only – check local conditions and ask your local school. Everything is calculated in your browser.

### How it works

Enter your weight and the wind speed, and choose your level for the board volume.

### Tips

- Check local conditions and safety rules before going out.
- Start with conservative equipment choices and adjust with experience.
- Every field has its own unit menu.
- Everything is calculated in your browser.

### Common mistakes to avoid

- Using estimates instead of a proper check in the water.
- Mixing feet and metres, or knots and km/h.
- Overestimating your skill in strong wind.

### Inputs explained

FieldWhat to enterSailor weightUnits: kg, lbWind speedUnits: kn, km/h, mph, m/sYour levelChoose one: Complete beginner (+130 L), Intermediate / cruising (+100 L), First short board (+60 L), Comfortable uphauling (+30 L) …

### What each result means

- **Wind** = [Wind speed]÷0.514444
- **Recommended sail size** = [Sailor weight]×1.34÷([Wind speed]÷0.514444)
- **Recommended board volume** = [Sailor weight] + [Your level]
- **Typical fin length** = [Sailor weight]×1.34÷([Wind speed]÷0.514444)×5.5

### Example values

How the main result changes when **Sailor weight** changes and everything else stays at the example values above:

Sailor weight (kg)Recommended sail size (m²)37.52.856.254.2755.693.757112.58.415011.2

## Worked example

Inputs — Sailor weight: 75 kg; Wind speed: 18 kn; Your level: Intermediate / cruising (+100 L).

Results — Wind = 18 kn; **Recommended sail size = 5.6 m²**; Recommended board volume = 175 L; Typical fin length = 31 cm.

## Key terms

- **Sinker**: Board with less volume than the sailor's weight.

## FAQ

**What sail size for beginners?**
Small sails (3–5 m²) in light wind while learning.

**What board volume floats me?**
Roughly your weight in kg as litres plus 20–30 L to uphaul.

**How much wind for planing?**
Usually 12–15 knots with the right gear.

**Does fin size matter?**
Yes – bigger sails need longer fins for grip.


## Sources

- [RYA – Windsurfing](https://www.rya.org.uk/)
- [Windsurfing Magazine – Gear guides](https://www.windsurfing.tv/)