Boat Speed Calculator

Calculate basic boat speed, theoretical hull speed, speed-over-ground vs speed-through-water, and fuel range in one tool.

Use the Boat Speed Calculator

Calculation Mode

Solve for Speed, Distance, or Time. Leave one field blank.

Enter values and click Calculate

Speed Unit Reference

Unit Knots km/h mph m/s
1 knot 1.000 1.852 1.1508 0.5144
1 km/h 0.5400 1.000 0.6214 0.2778
1 mph 0.8690 1.6093 1.000 0.4470
1 m/s 1.9438 3.600 2.2369 1.000

1 nautical mile = 1.852 km = 1.15078 statute miles

Summary

Calculate basic boat speed, theoretical hull speed, speed-over-ground vs speed-through-water, and fuel range in one tool.

How it works

  1. Choose a calculation mode: Basic Speed, Hull Speed, Current/SOG, or Fuel Range.
  2. Enter the required values for your selected mode.
  3. Results appear instantly in multiple units.
  4. For hull speed, enter waterline length in feet or meters.
  5. For current/SOG, choose "with current" or "against current" to adjust SOG and ETA.
  6. For fuel range, enter fuel capacity, consumption rate, and boat speed to get nautical range.

Use cases

  • Estimating travel time between two ports using knots or mph.
  • Finding the theoretical maximum efficient speed of a displacement hull.
  • Accounting for tidal current when planning a passage.
  • Calculating how far a boat can travel on a tank of fuel.
  • Converting speed between knots, mph, km/h, and m/s.

Frequently Asked Questions

Last updated: 2026-09-22 · Reviewed by Nham Vu