Energy fundamentals

How to Read an Appliance Power Label

Find voltage, current, watts, and duty-cycle clues on an appliance label.

The essential idea

Start with the nameplate or power adapter. A label may list watts directly or list volts and amps. For a simple estimate, volts multiplied by amps gives volt-amperes; this is not always identical to real watts for AC equipment.

How to apply it

Maximum label power can overstate normal energy use when a compressor, heater, or motor cycles. A plug-in energy meter can measure accumulated watt-hours over a representative period.

A practical decision

Use the maximum rating to check equipment limits and measured average consumption for runtime or cost planning.

Use this in a calculator

Browse all home energy calculators and replace the examples with measured or manufacturer-provided values.

Last reviewed: August 6, 2026