Hull Speed Calculator

Find a displacement hull's theoretical top speed.

Hull speed (knots) 6.7

Hull speed 7.71

Hull speed 12.408

Formula: hull speed = 1.34 × √(waterline length in ft)

Step-by-step with your numbers:

1. Values used:

2. Waterline length = 25

4. Hull speed = 6.7knots

5. Hull speed = 7.71

6. Hull speed = 12.408

Did we solve your problem today?

Hull speed is the practical top speed of a displacement boat.

The math behind it

hull speed (knots) = 1.34 × √(waterline length in feet).

25 ft waterline → 6.7 knots.

Can boats exceed it?

Planing hulls can; displacement hulls struggle past hull speed.