Online Tools

    Electrical Power Calculator

    Calculate DC, single-phase AC and three-phase AC electrical power, apparent power, reactive power and power factor correction.

    Single-phase AC: the result shows apparent, active, and reactive power using the power factor.
    Supply:
    Load:

    Educational estimate for power and load checks. Select wiring, breakers, protective devices, and capacitor banks from the project design, applicable standards, and equipment datasheets.

    Electrical power in circuits

    The page targets circuit power calculations: watts for DC and real/apparent/reactive power for AC loads.

    DC or unity-power-factor single-phase power.

    Single-phase AC real power with power factor.

    Balanced three-phase real power using line voltage and line current.

    Power factor caveat

    Educational estimate
    Do not size wiring, breakers, motors or capacitor banks from this page alone. Use applicable electrical codes and qualified design.

    Frequently Asked Questions

    Sources and References

    Calculations are based on the listed reference sources. Links open in a new tab.

    Updated:

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