Displacement / Length Ratio Calculator
Enter displacement and waterline length to compute the D/L ratio — how heavy a boat is for its length.
Pounds.Kilograms.
Feet.Metres.
The D/L formula
D/L = Displacement(long tons) ÷ (0.01 × LWL)³, where displacement in long tons = pounds ÷ 2240. It normalises weight against waterline length so boats of different sizes can be compared.
How to read it
- Under 100 — ultralight (racers, sport boats).
- 100–200 — light displacement.
- 200–300 — moderate.
- Over 300 — heavy bluewater cruiser.