Sailing performance guide
Capsize screening formula
The capsize screening value is a coarse comparison of beam and displacement, originally intended as a screening tool.
CSF = beam (ft) ÷ [displacement (lb) ÷ 64.2]^(1/3)
What it can tell you
Lower values tend to be associated with narrower or heavier boats. The often-cited threshold of 2.0 is a historical screening convention, not a universal boundary between safe and unsafe boats.
What it misses
The formula ignores ballast location, hull shape, downflooding points, dynamic stability, condition, loading, and seamanship. Never use it alone for an offshore-suitability decision.
Apply it to a real design
Calculate these metrics for a sailboat, then compare the result with catalog models.
Open the calculator