Enter the voltage, current, efficiency, and power factor into the calculator to determine the motor capacity.

Motor Capacity Formula

The following formula is used to calculate the motor capacity.

MC = (V * I * E * PF) / 746


  • MC is the motor capacity (horsepower)
  • V is the voltage (volts)
  • I is the current (amperes)
  • E is the efficiency (decimal)
  • PF is the power factor (decimal)

To calculate the motor capacity, multiply the voltage by the current, then multiply the result by the efficiency and the power factor. Divide the result by 746 (since 1 horsepower is equivalent to 746 watts) to convert the result to horsepower.

What is a Motor Capacity?

Motor capacity refers to the maximum amount of work that a motor can perform under specific conditions. It is usually measured in horsepower or watts and is determined by factors such as the motor’s size, design, and the materials used in its construction. The motor capacity is an important factor to consider when selecting a motor for a particular application, as it indicates the level of load the motor can handle without overheating or failing.

How to Calculate Motor Capacity?

The following steps outline how to calculate the Motor Capacity using the given formula:

  1. First, determine the voltage (V) in volts.
  2. Next, determine the current (I) in amperes.
  3. Next, determine the efficiency (E) as a decimal.
  4. Next, determine the power factor (PF) as a decimal.
  5. Using the formula MC = (V * I * E * PF) / 746, substitute the values of V, I, E, and PF into the formula.
  6. Finally, calculate the Motor Capacity (MC) in horsepower.
  7. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge:

voltage (V) = 220 volts

current (I) = 10 amperes

efficiency (E) = 0.85

power factor (PF) = 0.9