Boat Fuel Range Calculator

Summary

Enter your tank size, burn rate, boat speed, and reserve percentage to instantly see your safe range in nautical miles and time underway.

How it works

1. Enter your total fuel tank capacity in gallons or liters.
2. Set a reserve percentage (typically 10–25%) — this fuel is kept back for emergencies.
3. Enter your fuel burn rate (gallons per hour or liters per hour) at cruising throttle.
4. Enter your cruising speed in knots.
5. The calculator shows usable fuel, safe range in nautical miles, total time underway, and fuel remaining at destination if you enter a target distance.

Use cases

• Plan offshore passages and confirm you have enough fuel to reach the next marina.
• Calculate round-trip range so you can return to your departure point safely.
• Estimate how long you can run the engine before stopping to refuel.
• Compare fuel efficiency at different throttle settings and speeds.
• Verify a trip is safe before departure rather than discovering a shortfall underway.
• Set a realistic reserve for unexpected headwinds, currents, or detours.
• Calculate remaining fuel after reaching a waypoint at a known distance.
• Teach new crew members how range, burn rate, and reserves are related.

Frequently Asked Questions