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Keel Weight Calculator

Calculate keel weight, ballast requirements, and stability characteristics for your sailboat design.

Quick Samples
Try these common configurations to get started

30ft Cruising Sailboat

Typical modern cruiser

25ft Racing Yacht

Performance-oriented design

35ft Full Keel Cruiser

Traditional, heavy displacement

Hull Dimensions
Enter your boat's principal dimensions
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About This Tool
This calculator helps determine the optimal keel weight and ballast requirements for a sailboat. By inputting your boat's dimensions and desired keel characteristics, you can get a detailed analysis of the resulting keel's weight, ballast ratio, and overall efficiency. Proper keel design is a critical balance between stability, performance, and draft, and this tool provides the initial numbers needed to make informed design decisions.

Key Concepts:

Ballast Ratio: The percentage of the boat's total displacement that is ballast. Higher is more stable.
Keel Efficiency: A measure of the keel's hydrodynamic shape (aspect ratio). Higher is better for upwind sailing.
Righting Moment: The force that brings a heeled boat back upright. More ballast, lower down, equals more righting moment.
Ballast Density: Different materials (lead, iron) have different densities, affecting the size of the keel for a given weight.
Frequently Asked Questions

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