Drone Flight Time Calculator

Estimate how long your drone can fly from its battery capacity, voltage, safe usable discharge percentage, and average power draw during flight.

Quick Facts

Formula
Flight time = (Capacity(Ah) × Voltage × Usable%) ÷ Avg power × 60
Most pilots land with 20-30% capacity in reserve, so usable capacity is typically 70-80%, not 100%.

Your Results

Calculated
Flight time per battery
-
At your average power draw
Usable energy
-
Available before reserve cutoff
Average current draw
-
Implied by power ÷ voltage
Total mission time
-
Across all batteries carried

Ready

Enter your battery and power specs, then press Calculate.

Understanding the Drone Flight Time Calculator

This tool estimates how long a drone can stay airborne on a single battery, using the same energy-budget approach that RC and FPV pilots use to plan flights. It converts your battery's usable energy — measured in watt-hours — into minutes of flight at your typical power draw, then multiplies by the number of charged batteries you carry to estimate total time in the air for a mission.

The formula

Flight time is a straightforward energy-over-power calculation:

  • Usable energy (Wh) = Battery capacity (Ah) × Battery voltage (V) × Usable capacity (%)
  • Flight time (minutes) = Usable energy (Wh) ÷ Average power draw (W) × 60
  • Average current draw (A) = Average power draw (W) ÷ Battery voltage (V)
  • Total mission time = Flight time per battery × number of batteries carried

Battery capacity is normally rated in milliamp-hours (mAh); divide by 1,000 to get amp-hours (Ah) before multiplying by voltage. A 5,000 mAh, 4S LiPo pack (nominal 14.8 V) holds 5 × 14.8 = 74 Wh at full charge — but not all of that is usable in practice.

Why usable capacity matters

LiPo batteries lose capacity fast and can be permanently damaged when discharged too low, and a pilot needs enough reserve to navigate back and land safely. That is why most flight-time estimates use 70-80% of rated capacity as "usable," landing with 20-30% still in the pack rather than running it to empty. Setting usable capacity to 100% shows the theoretical maximum, not a realistic flight plan.

Where the average power draw number comes from

  • Manufacturer specs often list a hover-power or average-current figure for stock configurations.
  • Flight controllers and telemetry logs can report average current draw during a flight, which you multiply by pack voltage to get watts.
  • A bench test with a wattmeter under load gives a direct power reading for custom builds.

Power draw rises with payload weight, wind resistance, aggressive maneuvering, and cold temperatures, and falls in calm air with a light payload — so treat the figure as a flight-specific average, not a fixed constant.

Precision note

This is an energy-budget estimate, not a live telemetry reading. Real flights vary with wind, temperature, battery age and health, and flying style, so use the result to plan conservative mission legs rather than as a guaranteed number, and always fly with a safety margin above the calculated minimum.

Frequently Asked Questions

What is the standard drone flight time formula?
Flight time in minutes equals usable battery energy in watt-hours divided by average power draw in watts, times 60. Usable energy is battery capacity in amp-hours multiplied by voltage multiplied by the usable discharge percentage: (Capacity(Ah) × Voltage × Usable%) ÷ Average power(W) × 60.
Why isn't 100% of the battery usable?
LiPo batteries degrade quickly and can be damaged by full discharge, and pilots need reserve capacity to land safely. Most operators treat only 70-80% of rated capacity as usable, landing with 20-30% remaining rather than flying the pack to zero.
How do I find my drone's average power draw?
Check the manufacturer's hover-power or average-current specification, read it from a flight controller's power log (average current in amps times pack voltage), or measure it on a bench with a wattmeter. Wind, payload, and flying style all shift this number, so treat it as an average, not a constant.
Does carrying more batteries always mean more total flight time in the air?
Total airborne time scales with the number of charged batteries carried, since each one delivers roughly the same flight minutes. It does not shorten battery swap time or charging time between flights, so real mission duration is longer than the calculated airborne total alone.

Related calculators