Weight × wind rule-of-thumb calculator
Area (m²) ≈ weight (kg) × 2.2 ÷ steady wind (knots). This is an estimate from the cited handbook, not a kite recommendation. Check the specific manufacturer’s chart and local instruction.
What this calculation actually does
The formula is reproduced in Peter’s Kiteboarding Handbook as a contributed practical estimate. This page shows the arithmetic directly and does not add invented skill, board or confidence multipliers. A decimal result is an estimate, not a measurement proving that a product of that exact size is suitable.
The wind unit matters. The formula expects knots, while the GoNoGo weather scorer uses km/h. The two tools are shown separately to prevent a mean-wind equipment estimate from being mistaken for the scorer’s gust-based suitability band.
Cross-check equipment before treating the answer as useful
Kites of equal area can have different characteristics, and a board, rider and launch area can change the practical choice. This calculator has no manufacturer database and cannot assess those differences. Follow the actual equipment documentation and competent instruction rather than rounding a calculated answer into permission to launch.
A smaller numerical area is not a remedy for every bad forecast. Gusty conditions, offshore wind, storms and an unsuitable launch are separate issues. No result is displayed for missing, non-finite or non-positive inputs, and the tool never converts an undefined division into an equipment recommendation.
Worked examples from the existing scorer
These complete hypothetical hours run through the same scoring functions used by the live tool. They are not observations or forecasts. The displayed effective score includes any cap.
| Example | Effective score | Verdict | Model reasons |
|---|---|---|---|
| Illustrative rideable band | 100/100 | GO | No model penalties |
| Stronger gust | 64/100 | MAYBE | strong — experienced riders only · MAYBE cap |
| Storm regardless of size | 5/100 | NO-GO | thunderstorms — lightning on water · NOGO cap |
Exact example inputs and units
temp and feels: °C; wind and gust: km/h; precipitation: mm/h; visibility: m; rain probability, cloud and humidity: %. Weather code is WMO; UV is an index. Pressure, where shown, is context in hPa and does not affect this scorer.
[
{
"example": "Illustrative rideable band",
"inputs": {
"temp": 15,
"feels": 15,
"precip": 0,
"pop": 0,
"wind": 15,
"gust": 20,
"vis": 20000,
"code": 0,
"cloud": 10,
"humidity": 60,
"uv": 0,
"pressure": 1010
}
},
{
"example": "Stronger gust",
"inputs": {
"temp": 15,
"feels": 15,
"precip": 0,
"pop": 0,
"wind": 25,
"gust": 45,
"vis": 20000,
"code": 0,
"cloud": 10,
"humidity": 60,
"uv": 0,
"pressure": 1010
}
},
{
"example": "Storm regardless of size",
"inputs": {
"temp": 15,
"feels": 15,
"precip": 0,
"pop": 0,
"wind": 15,
"gust": 20,
"vis": 20000,
"code": 95,
"cloud": 10,
"humidity": 60,
"uv": 0,
"pressure": 1010
}
}
]Planning bands and the limits of the number
The existing model starts at 100, subtracts its condition penalties and applies critical caps. GO is 70–100, MAYBE 45–69 and NO-GO 0–44. A MAYBE cap limits the effective score to 64, and a NO-GO cap to 40. These are application suitability bands, not certified safe operating limits.
Rain branches are alternatives: matching probability, intensity and weather-code triggers do not mean adding the same rain penalty repeatedly. Separate factors can combine. A cap prevents benign temperature or dry weather from cancelling a critical flagged condition. Use the reasons beside the result to understand what changed.
The model requires complete numeric weather inputs. Missing visibility, rain probability or another required value returns Insufficient data; it is never filled with an invented favourable value. Local warnings, closures, equipment instructions and actual observations can change your decision even when the model returns GO.
Read the full kitesurf methodology and thresholds. The model and these examples were cross-checked on 18 October 2026. No physical field-test or safety certification is claimed.
Equipment and an alternative plan
Enter weight and a steady-wind value with the units shown, read the calculation as a rough estimate, then check the actual kite chart and local conditions. Keep the option to change equipment, seek instruction or stay ashore. The live weather verdict is a separate planning aid.
Questions about Kite size calculator: weight and wind as a rule of thumb
Is this a manufacturer-approved sizing chart?
No. It is a sourced rule of thumb and has no model-specific approval.
Should I enter the strongest gust?
No. This estimate labels its input as steady wind in knots; inspect gusts separately.
Does a calculated area mean it is safe to launch?
No. Direction, launch space, equipment and competence still need separate judgement.
Sources and limits
The numeric application bands come from the existing GoNoGo scorer and methodology. External guidance is linked for its stated context; it is not presented as endorsement of this model.
Live forecast data is supplied by Open-Meteo. An illustrative model output is different from a live forecast, and a forecast is different from a local observation.