Hull Speed Calculator – Calculate Maximum Hull Speed

Waterline Length (LWL) ?

Unit

Quick Set:

Hull Constant (C) 1.34 ?

Heavy 1.0Average 1.34Ultra-light 1.6

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knots

THEORETICAL HULL SPEED

— knots

Typical range: —

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km/h

—

mph

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m/s

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S/L Ratio

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Froude (Fr)

1 NM: — 10 NM: — 100 NM: —

Hull Speed is the theoretical maximum speed a displacement hull can achieve before wave-making resistance rises sharply. Formula: V = C × √LWL (V in knots, LWL in feet). C is the hull constant (default 1.34). The Froude number indicates flow regime: <0.4 displacement, 0.4‑0.6 semi-displacement, >0.6 planing.