Drones these days, arrive in a variety of different sizes. Obviously, it is the new technology, and it has been made and modified into so many different models. You can get a drone in whatever size you like. How much power do they use? Here are some examples:

**1. A Mavic Air uses 44 Watts/hour.**

**2. A Mavic 2 uses 59 watts/hour.**

**3. A DJI Spark uses 17 watts/hour.**

**4. Holy Stone HS700D 21 watts/hour.**

One thing that is worth noticing is that the flying time is directly proportional to the size of the drone that you have. The bigger the drone, the more is its flying time. However, the smaller drones cannot even last five minutes in the air sometimes.

On the other hand, the bigger ones are capable of going half an hour in the air, easily. Why do you think, that a larger, and more probably a heavier drone would last longer in the air? To understand this phenomenon, we would have to probe deeper into the science of the drones.

Watt is the unit of power. How do you estimate the power that is needed by a drone to hover in the air? Let’s suppose you have a drone with the rotors that spin. It doesn’t matter how many rotors you have. They could be one, or way more than one as well.

What actually matters is that these rotors function by pushing the stationary rotors above them, downward. When the momentum of the air is increased, the rotor will exert a force on the air, and the air will push back on to the rotor. The drone will only be capable of hovering when the weight of the drone equals the weight of the air force.

Airspeed and size of rotors are directly proportional to each other. So, increasing the size means that you would be increasing the power in watts that are being used by the drone.

This is an important phenomenon when you want to determine the power, which can be expressed by using the following expression.

From this expression, we can deduce that the more area a rotor has, the more flying time it has. The power is going to depend upon the area of the rotors of the drone.

Power also depends upon the air pressure. The drone will use less power if its speed is low. On the other hand, if you make it fly at high speed, it will use more power.

Power is defined as the work done in a unit time. It is basically the rate at which a drone will use energy.

The power will be in watts if you will measure the energy in joules and time interval in seconds.

In a nutshell, a big drone is going to use more watts, and a smaller drone is going to