Fuel Planning

Planning Fuel You Can Rely On

Fuel planning is where regulation, arithmetic, and judgment meet. The rules set a floor — 30 minutes of reserve for day VFR and 45 minutes for night under 14 CFR 91.151, with IFR reserves defined in 91.167 — but experienced pilots plan to land with far more than the minimum. The tools in this category help you move from a burn rate and a distance to a complete, defensible fuel plan: how much you will use, how long you can stay airborne, how much the regulations require you to keep untouched, and how far the tanks will actually take you.

Getting this right is not academic. Fuel exhaustion and fuel starvation remain among the most preventable causes of general-aviation accidents, and nearly every one traces back to optimistic planning rather than a mechanical failure.

Which fuel tool should I use?

Begin with the fuel burn calculator to turn your power setting and flight time into gallons or pounds consumed. Use the endurance calculator when the question is how long you can remain aloft on the fuel aboard, and the aircraft range calculator when it is how far. Before you commit to any of it, run the reserve fuel calculator so the regulatory minimum is carved out first and never dipped into for planning.

A practical fuel-planning workflow

Chain the tools in the order you actually make decisions. First, compute reserve fuel for your operation and subtract it from usable fuel to find the fuel available for the trip. Feed your cruise burn rate into the fuel burn calculator to estimate trip consumption, then confirm with the range calculator that the remaining fuel covers the distance with margin for wind, diversions, and taxi. Use endurance to sanity-check holding or a longer-than-expected approach sequence. Because true airspeed and groundspeed change your time en route, cross-reference the true airspeed calculator and your navigation log when the winds are strong. Our VFR fuel planning guide works a full example end to end.

Common mistakes to avoid

The classic error is planning to the regulatory reserve rather than above it; the reserve is what remains after everything goes wrong, not a number you spend. Another is confusing usable and total fuel — only usable fuel counts toward endurance and range. Pilots also underestimate taxi, run-up, climb, and headwind burn, all of which happen at higher-than-cruise fuel flow. Finally, mixing units invites disaster: a US gallon is 3.78541 liters, an Imperial gallon is larger, and AVGAS weighs about 6.0 pounds per gallon — keep weight and volume straight, especially when a fuel receipt is in liters.

Limitations & how to verify

These calculators assume the burn rate you provide is accurate for the phase of flight; real consumption varies with power, mixture, altitude, and temperature. Treat the outputs as a plan to be confirmed by physically checking fuel quantity, by leaning per the POH, and by monitoring actual burn in flight. The regulatory reserves built into the reserve tool follow 14 CFR; verify the current text against the eCFR, and review our methodology and sources for the exact rules and factors used.

Related learning

Continue with our VFR fuel planning article and the printable flight-planning worksheets. Since fuel burn depends on speed and distance, the navigation calculators and the unit converters for gallons, liters, and pounds are natural next stops.