Free tool
Fuel & Endurance Calculator
Type your usable fuel, planned burn, and cruise speed and read back total endurance, still-air range, and whether you meet the 14 CFR §91.151 VFR fuel reserve — 30 minutes by day, 45 by night, at normal cruise. It works for any light single; the presets are a clearly-labeled PA-28 / Cherokee example you can overwrite with your own POH numbers.
Endurance is usable fuel divided by gallons per hour; range is that endurance flown at your still-air cruise speed. The reserve is simply the 30- or 45-minute burn held back before you plan the trip — the same arithmetic you would do on a kneeboard, shown step by step.
- Reserve (30 min)
- 4.3 gal
- Usable for trip
- 43.8 gal
- Plannable range
- 566 NM
After holding 4.3 gal for the 30-minute reserve, you can plan 5h 9m of flying — about 566 NM in still air.
Still-air numbers — real range shrinks with a headwind and grows with a tailwind, and taxi, run-up, climb, and unusable fuel all bite. The POH and your dipstick win; treat this as a planning check, not a fuel gauge.
More pilot tools
One of a growing set of free pilot tools. For the regulation and the reasoning behind the reserve, see the study guide.