Weather & Flight
Flight Time / Battery Calculator
Estimate practical flight time from your rated capacity, wind, cold and payload.
Planning aid only — not certified flight-planning software or airspace clearance. Always verify results against your own aircraft's manual and check current regulations before flying. Full disclaimer.
Estimated flight time
30.0 min practical
Reserve: 6.0 min (20%) · Usable: 24.0 min
Wind/cold/payload derating percentages above are general planning assumptions, not per-drone data — real flight-time loss varies by airframe and battery chemistry. Always keep a real safety margin and land with battery to spare.
Why rated flight time is optimistic
Manufacturers measure flight time in near-ideal conditions: a new, fully charged battery, mild temperature, no wind, and usually steady forward flight at an efficient speed. It is a useful figure for comparing drones, but real flights almost always end sooner, and a battery warning ends the flight well before the battery is actually empty.
This calculator starts from the rated time and reduces it for the conditions you choose, then keeps back a reserve so you land with charge to spare.
How the estimate is built
1. Derating for conditions. Each choice removes a percentage of the rated time:
| Wind | Reduction | Temperature | Reduction |
|---|---|---|---|
| Calm | 0% | Above 10°C | 0% |
| Breezy | 8% | 0 to 10°C | 8% |
| Windy | 18% | −10 to 0°C | 18% |
| Strong | 30% | Below −10°C | 30% |
Add your own percentage for extra payload, such as propeller guards, lights, a parachute or a heavier third-party battery. The reductions are added together and capped at 80%.
2. The reserve. The percentage you choose, 20% by default, is kept back from the practical time. What's left is the usable flight time: when you should be landing, not when the battery runs out.
Example: a drone rated for 30 minutes, flown in windy and cold conditions (18% + 18%), gives about 19.2 minutes of practical flight time. With a 20% reserve, the usable time is about 15.4 minutes.
These percentages are general planning figures, not measurements for your aircraft. The more you fly, the better you can adjust them from your own experience; a flight log helps.
Choosing the wind level
The wind levels aren't tied to fixed speeds, because the same wind is easy for a large drone and hard work for a small one. A practical way to choose is to compare the forecast wind at your flying height with your drone's rated wind resistance:
- Calm: hardly any wind.
- Breezy: well under half the drone's rating.
- Windy: around half to three-quarters of the rating.
- Strong: close to the rating. Consider whether to fly at all.
Check the wind at height with Wind at Altitude, and your drone's rating in our drone limits database. Our guide to drone wind ratings explains what the rating does and doesn't mean.
What the estimate leaves out
- Battery age. An older battery with many cycles holds less energy and sags more under load. Reduce the rated time for old packs.
- Hot weather and high elevation. Thin air makes the propellers work harder. Add a few percent to the payload field when flying high or on very hot days; see flying in hot weather.
- How you fly. Fast flight, repeated climbs and aggressive manoeuvres use much more power than a gentle cruise or hover.
- The return leg. If the wind will be against you on the way back, the last minutes of the flight cost the most. Check the return time with the Return-to-Home calculator.
Planning batteries for a mission
Enter a target mission length to see how many batteries you need at the usable flight time. Round up, and bring one more than that if you can: a battery that won't warm up, an aborted first flight or a site that takes longer than planned all use up spares. In cold weather, keep spare batteries warm until you use them; see how cold weather affects drone batteries.