A method you can check
Appliance labels often contain several numbers: voltage, frequency, current, input power, output capacity, and sometimes energy ratings. They are not interchangeable. For a basic electricity-use estimate, the useful figure is normally the electrical input power in watts (W) or kilowatts (kW).
Look for input power
Search the rating plate or manual for “input,” “rated power,” “power consumption,” or a value in W or kW. If a device lists 0.75 kW of electrical input, that corresponds to 750 W. Do not multiply a value already expressed in kW by another factor of 1,000 before using it in a kWh formula.
Cooling capacity is not electrical input
Air conditioners and heat pumps may prominently advertise cooling or heating capacity in BTU/h or kW of thermal output. That number describes heat moved, not electricity drawn. If you need to estimate electrical cost, obtain the electrical input rating or an appropriate energy-consumption figure from the manufacturer's documentation. Entering thermal capacity as electrical watts can produce a seriously misleading estimate.
Rated maximum versus typical operation
The rating plate is a good starting point, but some appliances vary their power with temperature, workload, motor speed, or program. For a washing machine, an energy-per-cycle label may better represent a typical cycle than multiplying the highest listed wattage by the whole cycle duration. For variable-speed HVAC, actual draw changes through the day.
Measure safely
A suitable plug-in energy meter can help with compatible plug-connected appliances. Follow the manufacturer's instructions and never open an appliance or expose wiring to obtain a measurement. Some equipment is hardwired or requires professional measurement; do not try to improvise a mains-voltage test.
Keep a note of the source
Write down whether your value came from a rating plate, manual, energy label, or direct measurement. That makes later comparisons more useful and helps you spot when two figures represent different modes.
Related resources
Continue with the Electricity Cost Calculator, the Home Energy Planner, or the Appliance Comparison Calculator depending on the question you are trying to answer.
References and further reading
The U.S. Federal Trade Commission explains how to use an EnergyGuide label when shopping for appliances, including why its estimated operating cost can differ from an individual bill. The U.S. Energy Information Administration also explains watts and kilowatt-hours.
EnergyGuide is a U.S. labeling system. Outside the United States, check the rating plate, instruction manual, and the energy-labeling system used in your country.