Drone Flight Time Calculator (From Battery and Power Draw)
Estimated flight time of a drone from its battery capacity and voltage, the share of it you use and the average power it draws, plus the distance at a given speed.
Results
What this tool does
Flight time is just the battery's energy divided by the power the drone draws. The energy in watt-hours is mAh × volts ÷ 1000, and a LiPo cell counts as 3.7 V nominal, so a 4S pack is 14.8 V. The number that decides everything is the average power, which depends on weight, wind, speed and how you fly; hover power is a sensible start, and a figure from a wattmeter in flight is far better. Not all the capacity is usable: flying a LiPo to empty damages it and leaves no reserve for landing, so many pilots stop around 20 % left.
Formula
minutes = (mAh × V ÷ 1000) × usable fraction × 60 ÷ average power in W
Variables
| Symbol | Meaning | Unit |
|---|---|---|
mah | Battery capacity | mAh |
v | Battery pack voltage (nominal) | V |
us | Share of the battery you actually use | % |
pw | Average power drawn in flight | W |
sp | Cruising speed | km/h |
MN | Flight time, minutes | min |
WH | Energy stored in the battery | Wh |
UW | Energy you actually use | Wh |
RG | Distance you can cover at that speed | km |
Worked example
- Battery capacity5000 mAh
- Battery pack voltage (nominal)14.8 V
- Share of the battery you actually use80 %
- Average power drawn in flight150 W
- Cruising speed30 km/h
- Flight time, minutes23.7 min
- Energy stored in the battery74.0 Wh
- Energy you actually use59.2 Wh
- Distance you can cover at that speed11.8 km
Limitations
- A battery does not give its full rated capacity at a heavy load: the higher the current, the less energy you actually get out. This calculation is linear, so treat it as an upper bound and use the efficiency field to allow for the difference.
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.