Windsurf Calculator

Every session on the water starts with the same question: what size should I take today? The answer depends on your weight, the wind, your skill level and the discipline — and it is usually hunted down in decade-old tables, in forum advice, or by trial on the water, once the wrong sail is already rigged.

The calculator answers that in seconds. You enter your weight and the wind — it gives you working sizes for windsurfing, kitesurfing and wingfoiling.

What it works out

• Windsurfing. Sail area, board volume and dimensions, mast and fin — by fin type: freeride, slalom, wave, formula, weed. Windfoil is covered separately, where board volume is chosen differently.
• Kitesurfing. Kite size for the wind and your weight, plus twintip length and width. Width matters more than length for early planing — the calculator accounts for that.
• Wingfoiling. Wing size and board volume. A beginner needs flotation to balance before getting on the foil; an advanced rider goes near-sinker.

How it differs from a table on the internet

A range, not a single number

For the sail and the fin you get five values: standard, weight-adjusted, underpowered, ideal and overpowered. The wind is rarely exactly what was forecast, and knowing the edges beats knowing the middle.

Skill taken into account

Beginner, intermediate, advanced — at the same weight and wind the sizes come out different, because the demands on stability are different too.

A check for the board you own

Not only what to buy, but whether what you already have will do. Enter volume, width and length and get a suitability verdict for your weight and conditions.

PRO modes

Std, Std+ and Adv change the model behind sail, wing and board volume: from conservative to aggressive. In PRO you can enter any sail area and build your own quiver, marking the gear you actually own — the calculator then works within your set, not an abstract one.

Graph

You see how the size shifts with the wind, not a single point.

Built on the James Douglass algorithm, a sizing method well known in the scene, extended with modern fin and board guidelines.

Who it is for

The beginner choosing a first kit who would rather not buy a sail to grow into and regret it. The experienced rider building a quiver with no gaps and no duplicates. Rental centres and schools sizing gear for a student by weight. And anyone who checks the forecast in the morning and decides what to load into the car.

Small things that make it pleasant

English and Russian, dark and light themes, knots or metres per second, works from a phone right on the beach.

windsurfcalc.nexiguard.io