Enter the true power and reactive power into the calculator to determine the apparent power.

Apparent Power Formula

The following formula is used to calculate the apparent power of a system.

A = Sqrt ( TP^2 + RP^2)
A = I^2 * Z
  • Where A is the apparent power (kVA)
  • TP is the true power (kW)
  • RP is the reactive power (kVAR)
  • I is the impedance current
  • Z is the impedance

To calculate the apparent power, multiply the impedance squared by the impedance.

Apparent Power Definition

Apparent power is a measure of the combination of reactive power and true power in a circuit.

Apparent Power Example

How to calculate apparent power?

  1. First, determine the true power.

    Calculate the true power of the circuit.

  2. Next, determine the reactive power.

    Calculate the reactive power of the circuit.

  3. Finally, calculate the apparent power.

    Calculate the apparent power using the formula provided above.


What is the difference between true power, reactive power, and apparent power?

True power (measured in watts) is the power that actually powers the devices and performs useful work. Reactive power (measured in volt-amperes reactive or VARs) is the power that oscillates between the source and load, not doing any useful work but necessary for creating magnetic fields required by inductive loads. Apparent power (measured in volt-amperes or VA) is the combination of true power and reactive power, representing the total power used by a system to produce the work and sustain the reactive loads.

How do you calculate apparent power in a circuit?

Apparent power can be calculated using the formula (A = sqrt{(TP^2 + RP^2)}) where (A) is the apparent power in kVA, (TP) is the true power in kW, and (RP) is the reactive power in kVAR. Alternatively, it can also be calculated using (A = I^2 * Z) where (I) is the current and (Z) is the impedance of the circuit.

Why is apparent power important in electrical systems?

Apparent power is important because it represents the total power that must be supplied by the source to both accomplish useful work and support the reactive power needed by certain components in the system. It helps in designing and sizing electrical infrastructure, ensuring that systems have adequate capacity not just for the actual work to be done (true power) but also to handle the non-working (reactive) power circulating in the system.

apparent power calculator
apparent power formula