If you're wondering how to extend the flight time of your quadcopter, you're in the right place: this drone flight time calculator lets you experiment with relevant parameters to find the best combination for your drone. We will also provide you with a simple quadcopter flight time formula that makes the otherwise complex calculations a breeze.
Drone flight time formula
Calculating the drone flight time seems like a daunting task, but it's actually quite easy. It's governed by a single formula:
time = capacity × discharge / AAD,
time– Flight time of the drone, expressed in hours.
capacity– Capacity of your battery, expressed in milliamp hours (mAh) or amp hours (Ah). You can find this value printed on your LiPo battery. The higher the capacity, the more energy is stored in the battery. *Check out our battery capacity calculator to calculate battery capacities.
discharge– Battery discharge that you allow during the flight. As LiPo batteries can be damaged if fully discharged, it's common practice never to discharge them by more than 80%. If you'd like to change this default value, type the required discharge into the respective field of this drone flight time calculator.
AAD– Average amp draw of your drone, calculated in amperes. If you know this value, open the
advanced modeto enter it directly into our calculator. If you're not sure how to calculate it, keep reading – we will help you determine the amp draw based on parameters such as the quadcopter weight or battery voltage.
Interested in other calculators related to LiPo batteries? Make sure to calculate the battery life, too!
How to calculate the amp draw?
If you're not sure what is your average amp draw, it's time to learn how to calculate it! It's quite simple. All you need to do is use the following equation:
AAD = AUW × P / V,
AAD– Average amp draw, expressed in amperes.
AUW– All-up weight of your drone – the total weight of the equipment that goes up in the air, including the battery. It is usually measured in kilograms.
P– Power required to lift one kilogram of equipment, expressed in watts per kilogram. Our drone flight time calculator assumes a conservative estimate of 170 W/kg. Some more efficient systems can take less, for example, 120 W/kg; if that's your case, don't hesitate to adjust its value.
V– Battery voltage expressed in volts. You will find this value printed on your battery.
If you're familiar with Ohm's law, you probably noticed that
P / V is the definition of an electric current
I. Hence, you can use an alternative version of the formula above:
AAD = AUW × I,
I stands for the current (in amps) required to lift one kilogram into the air.
Quadcopter flight time calculation
Let's analyze the following example: you want your drone to hover in the air for thirty minutes to take an aerial video. Will an 8.8 Ah battery be suitable for this job?
Determine the maximum discharge of the battery. In this case, you want to stick to 80%.
Find out the battery voltage. Let's assume it's 36 V.
Weigh your drone together with the LiPo battery. We can assume a weight of 2.5 kg.
Decide how many watts are required to lift one kilogram. We will take the conservative estimate of 170 W/kg.
Calculate the average amp draw:
AAD = AUW × P / V
AAD = 2.5 × 170 / 36 = 11.8 A
Finally, use the drone flight time formula:
time = capacity × discharge / AAD
time = 8.8 × 80% / 11.8 = 0.6 hrs = 36 min
The drone will hover in the air for 36 minutes, giving you more than enough time to shoot a 30-minute video.
Various flying modes
Remember that the time calculated with our tool might differ from the real flight time. We assume that your drone mostly hovers in the air – every time it performs some elaborate maneuvers, one of the motors has to work faster and hence uses up more current. You can use the following numbers as a rule of thumb:
If your drone only moves around slightly – for example, during aerial photography – the flight time will be about 75% of the calculated time.
If your drone flies in strong wind or moves around a lot, the flight time will decrease to around 50%.
If you're participating in FPV racing or flying at high throttle levels, the flight time will decrease to 25-30% of the calculated value.