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⚡ Wattage Calculator

Convert volts/amps/watts or calculate energy costs

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Watts (W)
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Kilowatts (kW)
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Volt-Amps (VA)

Understanding Electrical Power

Volts, Amps, and Watts

Voltage (V) is the electrical pressure that pushes current through a circuit. Amperage (A) measures the volume of electrical current. Wattage (W) measures the total power consumed: Watts = Volts × Amps. This relationship is known as Ohm's Law and is fundamental to understanding electrical systems.

AC Power and Power Factor

In AC circuits, the power factor accounts for the phase difference between voltage and current waveforms. Real Power (W) = Volts × Amps × Power Factor. Apparent Power (VA) = Volts × Amps. The power factor is 1.0 for purely resistive loads (heaters, incandescent bulbs) and less than 1.0 for inductive loads (motors, transformers).

Common Appliance Wattages

LED bulb: 5-15W, Laptop charger: 45-100W, Microwave: 600-1200W, Space heater: 1500W, Window AC: 500-1500W, Clothes dryer: 1800-5000W, Electric oven: 2000-5000W. Knowing these helps estimate your energy costs and avoid circuit overloads.