Sailboat calculators
Free, instant calculators for boat performance ratios and everyday passage planning.
Hull Speed Calculator
Theoretical hull speed from waterline length.
SA / Displacement Ratio
Rig power-to-weight from sail area and displacement.
Displacement / Length Ratio
How light or heavy a hull is for its length.
Comfort Ratio (Brewer)
Predict a boat's motion in a seaway.
Capsize Screening Formula
The ≤ 2.0 offshore-suitability screen.
Anchor Rode & Scope
How much rode to deploy for a safe scope.
Sailing Time / Distance / Speed
Solve passage time, distance or speed.