Brushless Motor KV To RPM Calculator

Ever wonder how to convert brushless motor kv to rpm? In ths article will tell you a sample formula, But before that you should know what’s the KV and RPM meaning? Therefore, the main parameters of motor constant explained to you first.

What’s the KV meaning?

KV is the main parameter of motor, it is measure the speed of motor. 1Kv is 1 revolution per minute meaning that apply 1 volt to an unloaded motor. KV is in proportion to Volt, 2 volts will rotate twice value of KV.

KV is related to the torque level of the motor, what’s the torque? It’s another concept of motor. For rough conclusion, a low kv motor can produce higher torque with bigger prop and can carry more volts at less currents for your drone, and vice versa.

Take an example,

Motors	Props	Thrust(g)	Current(A)
1306 3100KV	4045	369	10.8
2204 2300KV	4045	369	6.7

As you see above table chat, a 180mm FPV drone with 1306 3100kv motor can make the thrust 369g at 10.8A, And it with low 2204 2300KV motor can make exactly the same thrust as 3100kv but different at less currents only 6.7A.

For application, the lower KV motor is good for the drone, which is used to carry high weight, like DJI aerial photograph drone Insprise series. The high KV motor is suited to racing sport drone, like all kind of FPV.

What’s the PRM meaning?

RPM the full name is revolution per minute. It’s used as a measure of revolution of the motor, the most intuitive formulation is that how fast the motor will totate.

The motor RPM directly impacts the speed of the RC car as it determines the rotational speed of the wheels. A higher motor RPM means a more powerful motor, enabling the RC car to achieve faster speeds. Conversely, a lower motor RPM may result in a reduction in the RC car’s top speed.

In the RC car speed calculator, the motor RPM is used in the formula to estimate the theoretical maximum speed of the RC car. It serves as a fundamental value required for the calculation.

Brushless Motor KV To RPM

How to calculate motor RPM? First you should know how many factors impact the value of RPM? In theory, in order to get RPM value just need to know only 2 factors, there are KV value and battery voltage.

RPM = Motor KV Racing * Battery Voltage

For your convenience, below is auto formula to get the value of PRM, just need to enter the kv rating of motor and your battery voltage.

Obviously above brushless motor kv to rpm is very simplistic calculator base on ideal conditions. Nevertheless, you should reference this value of RPM when choosing THE BEST MOTOR FOR DRONE.

The best way to measure RPM

In fact, many factors affect the test result, such as battery discharge rating, motor windings, propeller loading and motor efficiency etc.

In order to more accurately meausre the PRM, I suggest that use the professional tool to help. Below product is a great tool to measure the RPM of motors. A handy tool for checking the PRM of Brushless Motors. Click the image to purchase it.