Amps to Watts Calculator

Converting amps to watts tells you how much power a circuit or device is consuming — useful for sizing generators, checking circuit loads, or understanding energy use. Enter your Current (Amps), Voltage (Volts), and select your Current Type (DC, AC single-phase, or AC three-phase) to get your result in Watts and Kilowatts. For AC circuits, enter a Power Factor (0–1) and, for three-phase, specify your Voltage Type — the calculator also shows the exact formula used.

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Only applies to AC circuits (0-1)

Results

Power (Watts)

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Power (Kilowatts)

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Formula Used

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Frequently Asked Questions

What are amps, volts, and watts?

Amps measure electric current (flow of electricity), volts measure voltage (electrical pressure), and watts measure power (rate of energy consumption). Think of amps as water flow, volts as water pressure, and watts as the total work done.

What is the basic formula for amps to watts conversion?

For DC circuits: Watts = Amps × Volts. For AC single-phase: Watts = Power Factor × Amps × Volts. For AC three-phase: Watts = √3 × Power Factor × Amps × Voltage.

What is power factor and why does it matter?

Power factor is a measure of how effectively electrical power is used in AC circuits, ranging from 0 to 1. A power factor of 1 means perfect efficiency, while lower values indicate less efficient power usage. It only applies to AC circuits, not DC.

What's the difference between line-to-line and line-to-neutral voltage?

In three-phase systems, line-to-line voltage is measured between any two phases, while line-to-neutral voltage is measured between one phase and the neutral point. Line-to-line voltage is typically √3 times higher than line-to-neutral.

Can I use this calculator for both AC and DC circuits?

Yes, this calculator works for DC circuits (no power factor needed) and both single-phase and three-phase AC circuits. Simply select the appropriate current type and the calculator will use the correct formula.

What are typical power factor values for common devices?

Resistive loads (heaters, incandescent bulbs) have a power factor near 1.0. Motors typically range from 0.7 to 0.9. Fluorescent lights are around 0.5 to 0.95. Electronic devices vary widely from 0.5 to 0.9 depending on design.

How do I convert watts to kilowatts?

Divide watts by 1000 to get kilowatts. For example, 1500 watts = 1.5 kilowatts. This calculator automatically shows both values for your convenience.

Why is this conversion important for electrical work?

Converting amps to watts is essential for cable sizing, breaker selection, and determining total system power requirements. It helps ensure electrical safety and proper system design by calculating the actual power consumption from current and voltage values.