What Is motor KV? How to read brushless motor specs


If you’ve ever looked at a motor or are looking to buy one, you will notice they have printed values on them, if you have ever wondered what they all mean, this article will explain the motor codes and assist you in making your next motor purchase.

Decoding A Standard Brushless Motor


Printed Numbers: x2204S-16 and KV:2300, some details are vendor specific, but the internationally accepted parts are the 4 digit dimension code and the KV rating.

  • 2204: Represents the dimensions of the motor case and splits into 2 parts; the first two numbers are diameter; the last 2 numbers are height. This number may be in the middle of other letters and model numbers but is easily distinguished as 4 separate numbers.
    • From the SunnySky above we get:
      • 22mm for the diameter
      • 04mm for the height
  • KV:2300: KV states the relationship between volts and RPM. This is the no-load measurement so adding props and gears will reduce the actual RPM observed. KV is a good way to determine the max RPM your motor can achieve. A lower KV means more torque as per volt more energy is needed per revolution, a high KV motor will spin fast but have less strength. It can be challenging to get the perfect motor for your setup, so we recommend you first try a recommended configuration.
    • From the SunnySky above we get:
      • KV2300 means the motor will spin 2300RPM per volt applied to the motor.

 What else do I  need to know?

One crucial thing excluded from this standard code is the shaft diameter. This measurement should be on the product page or specification sheet. It is needed to ensure you get the right size propeller and connection.

Do you need a motor?

There a vast array of sellers online and we also specialize in parts, so if you are price hunting be sure to check out our range of Brushless motors.