MasterTool

Drone Flight Time Calculator

Calculate drone flight time from the published formulas and tables for the craft.

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What this tool does

Calculate drone flight time from the published formulas and tables for the craft. Battery Wh ÷ draw is an energy budget, not a flight test: wind, payload, aggressive flying and cold weather all raise real draw. If your battery is rated in mAh, Wh = mAh × nominal voltage ÷ 1000 (a 5,000 mAh 15.2 V pack is 76 Wh).

How to use the Drone Flight Time Calculator

  1. Enter or select battery energy (watt-hours, wh).
  2. Enter or select average power draw (watts).
  3. Enter or select reserve to keep in the battery (%).
  4. Read the calculated result; change any measurement to compare alternatives.

Formula

usable energy = battery Wh × (1 − reserve % ÷ 100); flight minutes = usable Wh ÷ average draw (W) × 60
wh
Battery energy (watt-hours, Wh)
draw
Average power draw (watts)
reserve
Reserve to keep in the battery (%)

Battery Wh ÷ draw is an energy budget, not a flight test: wind, payload, aggressive flying and cold weather all raise real draw. If your battery is rated in mAh, Wh = mAh × nominal voltage ÷ 1000 (a 5,000 mAh 15.2 V pack is 76 Wh).

Worked example

For drone flight time calculator, the following measurements illustrate the exact method: Battery energy (watt-hours, Wh): 68; Average power draw (watts): 200; Reserve to keep in the battery (%): 20.

Inputs

  • Battery energy (watt-hours, Wh)68
  • Average power draw (watts)200
  • Reserve to keep in the battery (%)20

Result

  • Estimated flight time (minutes)16.32
  • Usable battery energy (Wh)54.4
  • Flight time with no reserve (minutes)20.4
  • Energy kept in reserve (Wh)13.6

Results explained

Estimated flight time (minutes)
Estimated flight time (minutes) from the formula above. Battery Wh ÷ draw is an energy budget, not a flight test: wind, payload, aggressive flying and cold weather all raise real draw. If your battery is rated in mAh, Wh = mAh × nominal voltage ÷ 1000 (a 5,000 mAh 15.2 V pack is 76 Wh).
Usable battery energy (Wh)
Usable battery energy (Wh) from the formula above. Battery Wh ÷ draw is an energy budget, not a flight test: wind, payload, aggressive flying and cold weather all raise real draw. If your battery is rated in mAh, Wh = mAh × nominal voltage ÷ 1000 (a 5,000 mAh 15.2 V pack is 76 Wh).
Flight time with no reserve (minutes)
Flight time with no reserve (minutes) from the formula above. Battery Wh ÷ draw is an energy budget, not a flight test: wind, payload, aggressive flying and cold weather all raise real draw. If your battery is rated in mAh, Wh = mAh × nominal voltage ÷ 1000 (a 5,000 mAh 15.2 V pack is 76 Wh).
Energy kept in reserve (Wh)
Energy kept in reserve (Wh) from the formula above. Battery Wh ÷ draw is an energy budget, not a flight test: wind, payload, aggressive flying and cold weather all raise real draw. If your battery is rated in mAh, Wh = mAh × nominal voltage ÷ 1000 (a 5,000 mAh 15.2 V pack is 76 Wh).

Frequently asked questions

Divide usable battery energy by average power draw and convert to minutes: minutes = Wh × (1 − reserve) ÷ watts × 60. A 68 Wh pack flown to a 20% reserve at a 200 W average draw gives 68 × 0.8 ÷ 200 × 60 ≈ 16.3 minutes.

LiPo packs are damaged by deep discharge, voltage sags sharply at the end (risking a forced landing wherever you are), and you need energy to return and land. 20% is the common planning reserve; 25–30% is prudent in wind, cold or over water.

Multiply milliamp-hours by nominal voltage and divide by 1,000: a 5,350 mAh 15.2 V intelligent battery holds about 81 Wh. Use the nominal (not fully charged) voltage printed on the pack — manufacturers rate flight time from the same Wh figure.

Use your drone's hover draw as a baseline — roughly 150–250 W for a camera drone of 1–1.5 kg, far less for sub-250 g minis (30–60 W) and much more for heavy lifters. Telemetry logs from a real hover are the best source; add 20–50% for wind or sport flying.

The formula assumes a constant draw and a healthy pack at room temperature. Take-off and climb, wind fighting, payload, cold-soaked batteries and ageing cells all eat minutes — pilots generally treat any calculator (including this one) as an optimistic ceiling.