Methodology

What the calculators estimate

The main calculator estimates how long a specific drone can stay airborne on one battery under the conditions you give it: wind, temperature, humidity, altitude and terrain. Around it sit a mission planner that breaks a route into legs and tracks battery use per leg, a density altitude calculator, and pre-flight checklists organised by regulator. Every estimate is a planning figure, computed in your browser from the inputs on the page — nothing here is a measured result from a test flight.

The inputs

• Drone specifications — the database holds 440+ drones with their key specifications: battery capacity, nominal voltage, rated flight times (still-air and windy), weight and maximum wind resistance. Most records come from the manufacturers' published figures; where a manufacturer does not publish a value, a record may instead carry an estimated, calculated or community-sourced figure, and the catalog records which provenance each specification has. Either way, a drone without a valid rated flight time cannot be estimated at all — the calculator refuses rather than guessing.
• Your flight conditions — wind speed, temperature, humidity, altitude and terrain type. On pages that offer live conditions, current weather for the location comes from Open-Meteo; you can always override any value by hand. (Payload weight is an input on the enhanced calculator demo, not on the homepage calculator, whose estimate is for the drone as specified.)
• Battery state — capacity and chemistry (the tools cover LiPo, Li-ion, LiHV and other power sources the site models), because usable energy — not the label capacity — is what limits a flight.

How flight time is computed

The calculator does not invent a flight time from battery size alone. It starts from the two rated figures recorded for the drone — still-air flight time and windy flight time — and interpolates between them using a combined environmental efficiency computed for your conditions:

• Temperature — battery efficiency follows the curve the model implements: 100% across the optimal 20–25 °C plateau, 90% at 10 °C, 80% at 5 °C, 65% at 0 °C, 45% at −10 °C, 30% at −20 °C and 20% at −30 °C, with values interpolated between those points. Heat derates too: 85% at 30 °C, 65% at 40 °C and 25% at 55 °C. The temperature severity model explains the reasoning band by band.
• Wind — wind impact is computed from the wind speed against the drone's weight and published wind-resistance rating, adjusted for turbulence (severity, gust factor and terrain category). See the wind analysis guide.
• Altitude and air density — propeller efficiency is derived from the air density at your altitude, temperature and humidity (density-based scaling against standard sea-level density), so thin air reduces the estimate even before wind is considered. The standalone density altitude calculator shows the intermediate values.
• Humidity and terrain — humidity modifies efficiency (moist air is less dense), and the terrain coefficient you select adjusts for surface roughness and turbulence exposure.

The combined efficiency multiplies out those factors; the estimate then gives up that share of the gap between the rated still-air and windy times. The underlying energy relationship — flight time grows with usable battery energy and shrinks with power consumption — is documented in the battery estimation guide, and the learning library documents each factor in its own article.

Reserves and rounding

Pilot-facing flight times are truncated down to the whole minute, never rounded up. Beyond that, no hidden safety margin is applied: an optional safety margin (scaled by pilot experience and the drone's automation level, capped at 35%) is available in the calculator, but it applies only when you switch it on — the default estimate is the exact manufacturer-data-derived figure. Separately, our planning guidance in the battery estimation guide is to keep a battery reserve of 20% in normal conditions, 30% in wind, 40% in cold, and 50% when cold and high altitude combine, and to treat cell voltage as the honest fuel gauge: land by 3.4 V per cell and never discharge below 3.0 V per cell.

Data sources

• Drone and battery specifications: primarily manufacturer-published data, recorded per model in the drone database; where a published value does not exist, a record may carry an estimated, calculated or community-sourced figure, with its provenance recorded in the catalog.
• Weather: live conditions and forecasts via Open-Meteo, fetched when a page offers live weather.
• Regulatory checklists: the published rules of each regulator in the regulator database (FAA, EASA, CAA and others), summarised into pre-flight checklists.
• The models themselves: published aerodynamic and battery formulas with fully visible constants, documented article by article in the learning library — no hidden safety margins and no optimistic efficiency assumptions baked in silently.

Limits — what the estimates are not

• They are model outputs, not flight tests. Two flights in the same conditions can differ because of battery age and health, firmware behaviour, and how the aircraft is actually flown — none of which a calculator can observe.
• Manufacturer rated flight times are measured in controlled, near-ideal conditions; the model starts from them, so any optimism in a manufacturer's rating carries through unless the environmental derating removes it.
• Weather changes faster than any forecast. A live-weather estimate is only as current as the last fetch, and conditions at altitude differ from conditions at the launch point.
• Estimates are informational and never override the manufacturer's official performance data or your regulator's rules. Who runs the site, and how to reach us with a correction, is on the About page.