Advertised range is measured in still air, at optimum altitude and power, with a lightly loaded aircraft and no reserve. No real flight looks like that. This calculator discounts the brochure figure for reserve, wind and payload so you plan with a number that survives contact with reality.
How this calculator works
Planning range discounts advertised range for reserve, headwind and passenger payload.
Worked example
A published 1,000 nm range with a 20% reserve, an 8% headwind allowance and a 5% payload penalty becomes about 670 nm of one-way planning range — and a conservative 335 nm out-and-back radius without refuelling. That is the difference between a brochure map and a usable weekend.
Frequently asked questions
Why is real-world range so much less than advertised?
The advertised figure assumes still air, optimum cruise altitude, lean mixture, maximum fuel and often minimum payload. Add legally required reserves, a realistic headwind on one leg, climb fuel and passengers with baggage, and 60–70% of the brochure number is a healthy planning assumption for most missions.
What reserve should I plan with?
VFR minimums are 30–45 minutes of flight, and IFR with an alternate needs substantially more, but minimums are not plans. A 20% range reserve roughly covers the legal requirement plus routing detours and a diversion, which is why it is the default here.
What is an out-and-back radius?
The distance you can fly out and return from without buying fuel away from home — half the one-way planning range. It is often the honest measure of a touring aircraft, because avgas availability and price at the destination can be the real constraint on a weekend trip.
What to verify next
- Approved aircraft documentation and current limitations.
- Local fuel, insurance, maintenance, hangar and financing quotations.
- The exact aircraft configuration, loading and maintenance status.