Boat Speed Calculator

Calculate boat travel time, distance covered, or required speed in knots and mph from any two of distance, speed, and time, with hull speed for displacement boats.

Frequently Asked Questions

How fast is 10 knots?

About 11.5 mph or 18.5 km/h. Cruising speed for a 35-foot sailboat is typically 5-8 knots.

What is hull speed for a 40-foot boat?

1.34 · sqrt(40) = 8.47 knots. Below this, water resistance grows linearly; above it, resistance climbs steeply.

Can a sailboat go faster than hull speed?

Yes briefly, especially surfing down waves, but not sustained without planing. Planing requires a flat bottom and enough power - rare for displacement sailboats.

Important Disclaimer: Estimates for informational purposes only.

This calculator provides estimates for informational purposes only. Results are based on assumptions and may not reflect actual outcomes. Consult qualified professionals in relevant fields before making important decisions based on these results.