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Drone Motor Calculator

Table of contents

How much does your drone weigh?Drone thrust to weight ratioCalculating the motor thrust: an exampleFinal step: build your drone

This drone motor calculator helps you determine the thrust required of your drone motor to get your drone up in the air. Whether you're an amateur building your first drone, an aerobatics expert, or a photographer, you will surely find this tool to be of help.

How much does your drone weigh?

It's tricky to know the weight of your drone at the planning stage – after all, you didn't choose the motors yet, so how can you determine their weight? Nevertheless, a reasonable estimate is sufficient for our drone motor calculator. You can always adjust it later once you know more about the construction of your multicopter.

Check out our thrust-to-weight ratio calculator to learn the importance of weight and the thrust needed to lift it off the ground.

We split the total drone weight into three main components:

  • Drone weight is the weight of the main body – the frame, motors, propellers, landing gear, and so on.

  • Battery weight is the weight of your LiPo battery. Make sure you choose the right battery for longevity, too. Our battery life calculator can help you with that decision.

  • Equipment weight is the weight of detachable equipment – for example, if you're planning to use the drone for aerial photography, this will include the camera's weight.

Naturally, if you prefer to input the total weight of your drone directly, you can do it as well!

Drone thrust to weight ratio

Before you can determine the optimal thrust of the drone motor, you need to pick one more important parameter: the thrust to weight ratio.

Manufacturers of drone motors express the thrust in grams or ounces. This is the weight that one motor can lift off the ground. It doesn't mean, though, that a thrust equal to the drone's weight is sufficient! In most cases, you should plan for a 2:1 thrust-to-weight ratio to allow your drone to hover at just half throttle.

The higher the thrust-to-weight ratio, the easier it is to control your drone in elaborate aerobatics. You can use the 2:1 ratio for gentle flying (for example, for aerial photography). However, suppose you're planning to shoot FPV (first-person view) videos or participate in races. In that case, you should consider ratios such as 4:1 or 5:1. Extreme aerobatic flying could require a ratio as high as 7:1.

You should remember, though, that you will still need to accommodate a large battery if you want a long drone flight time.

Calculating the motor thrust: an example

Now that you know your drone's weight and preferred thrust-to-weight ratio for your flying style, you can finally determine the perfect motors for your drone. To do it, follow the steps below:

  1. Enter the weight of your drone into the appropriate boxes. We will analyze a drone with a body weighing 500 grams and a 4S LiPo battery weighing 150 grams. Additionally, we want to attach an FPV camera that puts an additional 50 grams on our drone.

  2. Pick the thrust-to-weight ratio. Let's assume we have just begun learning to shoot FPV videos, and a ratio of 3:1 will be sufficient.

  3. Determine the number of motors in your drone. We're building a quadcopter, so we will keep the default value of four.

  4. The drone motor calculator multiplies the total weight of our drone by the thrust-to-weight ratio and displays this value – in our case, 2100 grams – as the full thrust required for our drone.

  5. The last step is dividing the total thrust by the number of motors. We need four motors that will provide a thrust of at least 525 grams each.

Final step: build your drone

Now that you know what thrust is needed to get your drone flying, you need to find a motor type that fulfills your requirements. Then, you can readjust the total drone weight to take into consideration the actual motor weight.

For example, we found a drone motor with a thrust of 550 grams but weighing 15 grams more (in total) than we expected. After inputting the new weight into the calculator, we discover that the required thrust is now equal to 536 grams, below the performance of the chosen motor. It means we can safely use it for our drone.

If you like our drone motor calculator, make sure to take a look at the battery capacity calculator, too!


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