AC Wattage Calculator

Created by Luciano Mino
Last updated: Nov 05, 2022

The AC wattage calculator is the perfect tool to obtain the amount of electrical power in an alternating current circuit. It can also work as an AC current calculator if you know the wattage.

Within this short text, we will describe:

  • What AC wattage or AC power is;
  • How to calculate AC wattage;
  • How to use the AC power formula; and
  • Other features of this calculator.

Keep reading to learn more!

What is wattage?

Wattage is a measure of the amount of power used by an electrical device. It is commonly calculated by multiplying the alternating current (AC) voltage by the alternating current (AC) amperage or current. This calculation provides a rough estimate of how much power the device consumes and is typically expressed in units of watts (W).

There are a number of factors that can affect the amount of power consumed by an electrical device, such as its power factor. This is a measure of how effectively the alternating current is being used to power the device and can be calculated using a simple formula.

💡 Read more about wattage and power in our Electrical power calculator.

How to calculate AC wattage ─ AC power formula

To calculate wattage in AC circuits, we first need to know if the power is single-phase or three-phase.

For single-phase power, we will use the following formula:

P=pfIVP = pf\cdot I\cdot V


  • pfpf is the power factor;
  • II is the current;
  • VV is the voltage; and
  • PP is the power or wattage.

While for three-phase, we will use either of the following depending on the voltage we're working with:

  • P=3pfIVP = \sqrt{3}\cdot pf\cdot I\cdot V, if using the line-to-line voltage; and
  • P=3pfIVP = 3\cdot pf\cdot I\cdot V, if using line-to-neutral voltage.

🙋 Tip: you can also use this tool as an AC current calculator. Simply fill in every other field, and our calculator will automatically write the corresponding current value.

Luciano Mino
Current type
AC single phase
Power factor
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