Sailboat Performance Calculator

After many years of neglect (16 to be exact), I've finally rewritten this calculator to work properly in all browsers (hopefully). I've also prettied it up a bit and made it a bit more functional. Hope you find it useful! If you find any problems, please write me. (Mike 10/04/2011)

To use the calculator, simply fill in the fields for which you have values, then click the "Calculate" button. The performance characteristics for your boat will then be displayed. Note that only those characteristics that can be calculated from your input data are displayed. Have fun!!

Boat Info and Dimensions


Calculation Results

Metric Value Comment
Hull Speed
Sail Area/Disp

Formulas Used to Calculate Metrics

Hull Speed

Hull speed (measured in knots) is the theoretical limit at which your (displacement) hull can move through the water. It doesn't matter how much sail is in use, your boat can't go any faster than this in normal conditions. If you can plane, or are surfing, then you can/will exceed this speed, but then these aren't normal conditions, are they?

Displacement to Length at Waterline

This is a measurement of how heavy your boat is in relation to its length. Higher numbers mean you have a heavier boat. On the calculation page, and in my software, I give pithy comments on the probable performance characteristics of your boat depending upon this calculation.

Beam to Length on Deck

This number doesn't really have much to do with performance per se, but allows you to calculate the relative "beaminess" of a given vessel.

Sail Area to Displacement

This number measures the size of your sails versus the displacement of your boat. This is a measure of how likely you are to be able to get your boat to it's hull speed, but a good sail area to displacement ratio doesn't guarantee it. This figure, along with the displacement/LWL metric probably give you your best feel for the relative performance capacity of a given boat. home