Marine Displacement / Length Ratio Calculator
Calculate the conventional displacement to waterline length index from kg and metres.
A QUICK WALKTHROUGH
How to use this tool
- Enter positive displacement mass in kg.
- Enter positive waterline length in metres, not overall length.
- Calculate the numeric index, then copy or download the report.
Formula and units
Dlb = Dkg ÷ 0.45359237; LWLft = LWLm ÷ 0.3048. Index = (Dlb/2240) ÷ (0.01 × LWLft)^3.
Scope
2240 lb is one long ton, not a short ton. Use waterline length rather than length overall. This tool provides no vessel categories, performance, stability or passage recommendations.
Local processing
Inputs stay in your browser. The report includes inputs, formulas and scope.
GOOD TO KNOW
Common questions
Are short tons and overall length suitable?
No. This index uses long tons and waterline length with the stated conversions.