⛽ Boat Fuel Cost Calculator
Enter your engine's burn rate, the hours you'll run (or the distance and cruising speed), and the fuel price at the dock to see the gallons a trip needs and what it will cost.
🌊 Price a Day on the Water
⛽ Fuel for 4 hours on the water
What is a Boat Fuel Cost Calculator?
Cars think in miles per gallon; boats think in gallons per hour. This calculator speaks the marine language: give it your engine's cruise burn rate, how long you will run, and the pump price at the marina, and it returns the gallons the trip will drink and the bill at the fuel dock.
The cost-per-hour figure is the one to remember — it turns "let's stay out another hour" into a known number, and makes it easy to compare a slow scenic cruise against getting on plane and back. If you plan by chart instead of clock, switch to distance mode and let your cruising speed do the conversion.
❓ Frequently Asked Questions
How is boat fuel cost calculated?
Boats meter fuel by time, not miles: gallons = burn rate (gal/hr) × engines × hours run, and cost = gallons × price per gallon. If you know the trip as a distance instead, the calculator first converts it to hours by dividing by your cruising speed.
What burn rate should I enter?
Use your engine's cruise-RPM figure — a rough rule of thumb is one gallon per hour per 10 horsepower at wide-open throttle, and roughly a third to half of that at cruise. Your engine manual, fuel-flow gauge, or fill-up records give the real number.
How do twin engines change the math?
Select twin (or triple/quad) and the calculator multiplies the per-engine burn rate by the number of engines. Two 8 gal/hr outboards burn 16 gal/hr together — the hours and price math is otherwise identical.
Why is my real-world burn different from the estimate?
Load, sea state, hull fouling, and throttle discipline all move fuel burn — a choppy day with a full cooler can burn 20% more than a flat calm run. Treat the result as a planning figure and carry the boater's reserve: a third out, a third back, a third in reserve.