Volts to Watts Calculator

Converting volts and amps to watts tells you how much power a circuit or device is consuming — useful for sizing generators, checking electrical loads, or understanding energy usage. Select your circuit type (DC, AC Single Phase, or AC Three Phase), then enter your voltage and current values along with their units into the Volts to Watts Calculator. For AC circuits, add a power factor to get your real power output in watts and kilowatts.

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Only required for AC circuits

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Frequently Asked Questions

What is the difference between DC and AC power calculations?

DC power is calculated as P = V × I. AC power calculations require a power factor: single-phase AC uses P = V × I × PF, while three-phase AC uses P = √3 × V × I × PF.

What is power factor and when do I need it?

Power factor (PF) is a measure of how effectively electrical power is used in AC circuits. It ranges from 0.1 to 1.0, with 1.0 being ideal. It's only needed for AC circuit calculations.

Can I convert millivolts and milliamps to watts?

Yes, the calculator supports multiple units including millivolts (mV), volts (V), kilovolts (kV), milliamps (mA), amps (A), and kiloamps (kA). Units are automatically converted for accurate calculations.

How do I calculate watts for three-phase AC circuits?

Three-phase AC power uses the formula P = √3 × V × I × PF, where √3 ≈ 1.732. This accounts for the phase relationships in three-phase electrical systems.

What voltage and current values should I use for typical household circuits?

Household circuits typically use 120V or 240V. Common currents range from 1A for small devices to 20A for large appliances. Always use the actual measured values for accurate calculations.

Can this calculator help with solar panel power calculations?

Yes, if you know the voltage and current output of solar panels, you can calculate their power output in watts. This is useful for sizing solar systems and understanding energy production.

What's the relationship between volts, amps, and watts?

Watts measure electrical power, volts measure electrical pressure (voltage), and amps measure electrical flow (current). Power equals voltage multiplied by current: P = V × I.

How accurate are these power calculations?

The calculations are mathematically precise based on electrical laws. However, real-world factors like temperature, component tolerances, and line losses may cause slight variations from calculated values.