GM from Rolling Period

Estimate metacentric height by timing the vessel's natural roll.

Beam (m)

Full Rolling Period (seconds)

Rolling Coefficient f

Estimated GM

--m

Roll Period Used--

Stiffness--

GM ≈ (f × Beam ÷ Roll Period)². Time several complete rolls in calm water and average. An estimate only — not a substitute for the loading computer or stability booklet.