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Lofting & Scale Calculator

Scale dimensions from boat plans for lofting or model building.

Quick Samples
Try these common configurations to get started

Plan to Full Size

Common half-inch scale plan

Model Building

Creating a model from a full-size boat

Metric to Imperial

Converting metric plans

Hull Dimensions
Enter your boat's principal dimensions

e.g., inches, mm

e.g., 24 for 1/2"=1'

e.g., 1 for full size

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About This Tool
The Lofting Calculator is a simple but essential tool for any boat builder working from plans. It allows you to accurately scale any dimension from a drawing to a new size. This is the fundamental operation in lofting, whether you are drawing full-size on a workshop floor or creating a smaller or larger version of a design. Accurate scaling is the key to a fair and true hull.

Key Concepts:

Lofting: The process of drawing a design at full size to create patterns.
Scale: The ratio of a distance on a drawing to the corresponding distance in reality.
Fair Curve: A smooth, pleasing line without bumps or hollows, essential for hull shape.
Offsets: A set of coordinates from a drawing that define the shape of the hull.
Frequently Asked Questions

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