About the Drone Flight Time Calculator
This drone flight time calculator estimates how long a multirotor, FPV quad or camera drone can stay airborne on one battery. Enter the battery capacity in mAh, the number of cells and the chemistry, then the average current (amps) or average power (watts) the drone draws in flight. The result is the realistic flight time once you keep a safety reserve in the pack.
It is useful when choosing between battery sizes for a build, planning how many packs to bring for an aerial photo or survey job, or checking whether a manufacturer’s quoted flight time is plausible for your style of flying. Your average current is easiest to find from flight-controller logs, an OSD current sensor or by dividing the mAh you put back into the pack by the minutes flown.
The default 80% usable capacity follows the common practice of landing with about 20% remaining (roughly 3.7–3.8 V per LiPo cell at rest), which protects battery life. Wind, aggressive flying, payload and cold temperatures all raise the current draw, so treat the answer as a planning estimate rather than a guarantee.
With the default inputs, the flight time per battery is 12 min. Change any value above to recalculate instantly.
How to use the drone flight time calculator
- 1Enter the battery capacity printed on the pack, in mAh.
- 2Choose the cell count (the “S” number) and the chemistry.
- 3Enter the average current or power draw from your logs or OSD.
- 4Set how much of the pack you will use before landing — 80% is typical.
- 5Add how many batteries you will carry to see your total time in the air.
Formula and method
Capacity C in milliamp-hours is converted to amp-hours and multiplied by the usable fraction u, the share of the pack you are willing to drain. Dividing by the average current I gives hours of flight, and multiplying by 60 gives minutes. If you know the average power instead, the current is the power divided by the nominal pack voltage.
Nominal voltage is the number of cells in series times the nominal cell voltage: 3.7 V for LiPo, 3.85 V for high-voltage LiPo (LiHV) and 3.6 V for most Li-ion cells. The method assumes a steady average draw; in reality voltage sags under load and current rises as the pack empties, so real-world times are often slightly shorter.
- C
- Battery capacity (mAh)
- u
- Usable fraction of capacity (e.g. 0.8)
- I
- Average current draw (A)
- P
- Average power draw (W)
- V
- Nominal pack voltage (V)
Worked examples
5000 mAh 4S LiPo at 20 A average
Using 80% of 5 Ah leaves 4 Ah. At 20 A that lasts 4 ÷ 20 = 0.2 h, or 12 minutes. The pack stores 5 × 14.8 = 74 Wh and the drone uses about 296 W.
Small 3S 2200 mAh quad drawing 120 W
At 11.1 V, 120 W means about 10.8 A. Using 80% of 2.2 Ah (1.76 Ah) at 10.8 A gives about 0.163 h, or roughly 9.8 minutes per pack.
Long-range 6S Li-ion, 10,000 mAh, 3 packs
Li-ion cells average 3.6 V, so a 6S pack is 21.6 V and stores 216 Wh. Using 85% of 10 Ah at 15 A gives 8.5 ÷ 15 = 0.567 h, or 34 minutes; three packs give 102 minutes in the air.
Frequently asked questions
How do I find my drone’s average current draw?+
Check your flight controller or OSD log for average amps, or recharge the pack and divide the mAh put back in by the minutes flown, then multiply by 0.06. For example, 3,000 mAh after 10 minutes is 18 A.
Why use only 80% of the battery?+
Draining a LiPo below about 3.5 V per cell under load damages it and causes sudden voltage sag. Landing with roughly 20% left keeps the pack healthy and gives you a reserve for wind or a missed approach.
Will a bigger battery always give a longer flight?+
Not proportionally. A heavier battery increases the weight the motors must lift, which raises current draw. Beyond a point the extra capacity is mostly spent carrying itself, so flight time gains shrink.
How does cold weather affect drone flight time?+
Lithium batteries deliver less capacity and their voltage sags more in the cold, so flights end sooner and low-voltage warnings arrive earlier. Many drone makers advise warming packs before take-off in cold weather; keep spares in an inside pocket and hover briefly before flying hard.
What is the difference between mAh and Wh?+
mAh measures charge at the pack’s voltage, while Wh measures energy. Multiply amp-hours by voltage to get watt-hours, which lets you compare packs with different cell counts fairly.