Static Thrust Calculator

Where to find the calculator?

You will be able to download the calculator for free in the Technical data tab of our home page.

You can find a downloadable excel sheet named Static Thrust Calculator. We will need you to enter your email ID before downloading the file.

How this calculator is different from other online calculators?

There are many online static thrust calculators which give you approximate values.

But as a propeller manufacturer, we can say that these values may vary significantly. The reason is the RPM, torque, thrust depends on the aerofoil, chord and pitch distribution we use. The online static thrust calculators take only Diameter and number of blades into account.

Since we know our design (airfoil, chord and pitch distribution) we can give you precise values for your input. Also, this will not be accurate for other brand propellers as their design will be different.

All the values that are shown are based on real-time measurement of our props. So, this makes the data more reliable.

How does this calculator Work?

We have a range of multicopter propellers from 10’’ to 48’’ in diameter that is available Off the shelf. We measured the performance of every propeller. This calculator uses the performance of all these propellers and does interpolation and extrapolation based on the input.

Limitations of this Calculator

This calculator is only limited to multicopter propellers, which means you cannot enter the propeller pitch. The optimum propeller pitch for hover is automatically suggested and you cannot change it.

• The RPM and power values are applicable only for Mejzlik multicopter propellers
• The coaxial mode is not accurate, for now, the user has to input the expected loss in % for now and the mechanical power is offset based on the input. This will be fixed in the upcoming version of the calculator.
• The accuracy will reduce when we add more number of blades.
• There are some basic motor calculations included as well into this calculator but we recommend you to confirm with the motor manufacturer. The motor calculations are approximate and may vary based on motor manufacturers.

Do you already have the motor’s performance?

If you have any dyno test results or efficiency map of the motor you are going to use, please contact us we will be able to make some modifications and get the performance of any of our propellers with the given motor.

If you are a motor manufacturer who can provide such data and willing to cooperate please write to us.

How to use the calculator?

It is easier to explain this with a real-time example.

Let’s consider a quadcopter with 26’’ diameter propeller and take-off weight of 20 kg.

The thrust required to hover per propeller is 5 kg.

Below is the screenshot of the calculator.

In the input section enter the:

• Diameter (26’’)
• Thrust per propeller (5 kgs)
• If it is sea level leave the density as 1.225, but if you are flying at higher altitudes you can enter the air density to get the performance of the propeller at the required altitude.
• You can increase the number of blades if the tip speed exceeds 0.8M, or if the motor KV is too low and if you want to achieve the required thrust at lower RPM

In the output section, you can see the performance of the propeller for the specified thrust.

Additionally, in the graph section, you can see

• The change in mechanical power with the change in diameter of the propeller
• Thrust Vs RPM, g/W vs Thrust, Power vs Thrust curves.

You can also copy the complete propeller performance (in propeller performance sheet) for further analysis if needed.

This is just a brief introduction to the calculator.

For detailed information, please read the description and user manual sheet which is available in the calculator.

Disk Loading Calculator

The importance of disk loading is already discussed in one of our previous blog posts. You can find the link here.

In general, lower the disk loading, lower will be the required mechanical power for hover. Rotary wing aircraft with higher disk loading will lack endurance.

How to use the calculator?

It is easier to explain this with a real-time example. I’m considering the same case as the previous example.

Let’s consider a quadcopter with 26’’ diameter propeller and take-off weight of 20 kg.

The thrust required to hover per propeller is 5 kg.

Enter the Diameter and the required thrust per propeller for hover.

Entering the motor efficiency is optional, it is just to get the approximate electrical power consumption. In case if you want to check the endurance, you can also enter the battery parameters to get the hover flight time.

For this specific use case the disk loading is about 143 N/m2 which lies within the reasonable disk loading regime.

If it is a conventional rotatory wing aircraft then we recommend you to check if the disk loading is not greater than 250 N/m2

Disk loading will vary based on the application. Below are some of the applications where the disk loading can be high

1. If the power source has a higher power density than standard Lipo batteries.

2. If the aircraft has a variable payload, you will have to work out how the payload changes with time and optimize the setup efficiently to match the required endurance.

3. There are exceptions where the vertical takeoff or the hover phase is for a very short time. In this case, the disk loading can be slightly higher but remember higher the disk loading lesser the battery power remaining for the cruise flight.

4. Or if you want your aircraft to fly only for a very short duration then the disk loading can be changed accordingly.