Capsize Screening Formula Calculator
Enter beam and displacement to compute the Capsize Screening Formula (CSF) — a quick offshore-suitability check.
The Capsize Screening formula
CSF = Beam(ft) ÷ (Displacement(lb) ÷ 64)^(1/3). It weighs beam (which increases capsize risk) against displaced volume (which resists it). Developed after the 1979 Fastnet disaster as a fast first-pass screen.
How to read it
- 2.0 or less — considered better suited to offshore passages.
- Over 2.0 — better suited to coastal / inshore use.
It is only a screening number — hull shape, stability curve and seamanship matter far more than a single figure.