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.
Published range against planning range
Each row applies the calculator's default reductions to one aircraft's published still-air range: 20 percent reserve, 8 percent headwind and 5 percent for a payload that prevents carrying full fuel. The radius is the column that decides where you can go and come back in a day, and the last one says how long getting there takes.
| Aircraft | Published range | Planning range | Out-and-back radius | Time to the radius |
|---|---|---|---|---|
| Piper PA-28-140 Cherokee, single-engine piston | 500 nm | 335 nm | 167 nm | 1.6 h |
| Diamond DA42-VI, twin-engine piston | 1,225 nm | 821 nm | 410 nm | 2.3 h |
| Daher Kodiak 100 Series III, single-engine turboprop | 1,132 nm | 758 nm | 379 nm | 2.1 h |
| Beechcraft King Air 300, twin-engine turboprop | 1,560 nm | 1,045 nm | 523 nm | 1.6 h |
| Cessna Citation CJ1, light jet | 1,300 nm | 871 nm | 435 nm | 1.1 h |
| Robinson R44 Raven I, helicopter | 300 nm | 201 nm | 100 nm | 0.9 h |
What the table holds fixed
- Published range is the manufacturer's still-air figure, normally at long-range cruise with maximum fuel and minimum payload.
- The same 33 percent total reduction applies to every row, which is why the radius lands at about a third of the published range whatever the aircraft. The ranking is the published one.
- The time column divides the radius by published cruise speed in still air. It is block time only in the sense that it ignores climb, descent and any wind at all.
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.