Resistance Calculators
Hydrodynamic Resistance & Propulsion Sizing Suite
William Froude Resistance & Powering Calculator
Auditable model-to-ship resistance extrapolation and effective/installed power prediction based on Froude scaling and ITTC protocols.
Holtrop & Mennen Resistance Calculator
Power prediction method for displacement ships based on regression analysis of model test results and full-scale data.
Savitsky Planing Hull Calculator
Resistance, EHP, BHP, required power, and marine diesel engine matching for planing hulls using the Daniel Savitsky method.
Insel & Molland Catamaran Calculator
Resistance, EHP, BHP, and propulsion-engine matching for catamaran hulls using an Insel & Molland-style interference structure.
John H. Michell Theory
Theoretical wave resistance calculations based on thin-ship theory, integrated with empirical friction coefficients.
Leo Lazauskas / Michell-based
Advanced numerical wave resistance and trim evaluation tailored for slender monohulls and catamaran designs.
Hollenbach Resistance Calculator
Modern regression-based estimation method for single-screw cargo vessels and tankers.
Delft Series Resistance Calculator
Systematic yacht hull series analysis for sailing vessels and keel resistance profiles.
ITTC Frictional Resistance Calculator
Calculates the frictional resistance coefficient using standard ITTC-57 correlation line formulation.
Total Resistance Calculator
Combines frictional, wave-making, appendage, air, and correlation allowance components to compute total resistance.
Residuary Resistance Calculator
Extracts viscous/wave residuary resistance elements from physical basin scaling tests.
Wave Resistance Calculator
Estimates wave-making and wave-breaking resistance utilizing Michell integral and slender-body theories.
Air Resistance Calculator
Evaluates wind drag and superstructure aerodynamic resistance based on projected frontal area.
Appendage Resistance Calculator
Calculates additional drag penalties caused by rudders, shafting brackets, thrusters, and stabilizing fins.
Correlation Allowance Calculator
Determines the model-ship correlation factor (CA) for surface roughness and scale adjustments.
Form Factor (k) Calculator
Determines the Prohaska form factor coefficient (k) representing three-dimensional viscous pressure drag.
Effective Horsepower (EHP) Calculator
Converts total hydrodynamic resistance drag directly into towing power outputs.