Calculate Real Appliance Electricity Costs
Watts ÷ 1,000
Kilowatt conversion
Hours × Days
Monthly operating time
$/kWh Rate
Local utility pricing
To calculate monthly operating costs, divide nameplate wattage by 1,000 to find kilowatts. Multiply by effective daily running hours, days per month, and your local electricity rate per kilowatt-hour.
Window Air Conditioner
Electric Space Heater
50-Pint Dehumidifier
An 8,000 BTU unit at 720 watts running 8 hours daily with a 50% compressor duty cycle consumes 86.4 kWh monthly, costing approximately $13.82 at $0.16 per kWh.
A standard 1,500-watt space heater running 6 hours daily at full power consumes 270 kWh monthly, adding roughly $43.20 to your monthly electricity bill.
A 50-pint dehumidifier drawing 420 watts running 12 hours daily with a 60% duty cycle consumes 90.7 kWh monthly, resulting in $14.51 in monthly operating costs.
Why Cycling Power Changes Calculations
Compressor-based appliances like air conditioners and dehumidifiers do not draw full nameplate wattage continuously. When the room reaches the set thermostat temperature, the compressor cycles off while the fan continues operating at low wattage.
Space heaters with active thermostatic controls operate on a similar intermittent duty cycle. Accounting for effective operating hours rather than total plugged-in hours prevents overestimating monthly bill impacts across seasonal weather swings.
Appliance Deep Dives
Review specific duty-cycle breakdowns and wattage benchmarks for individual household appliances.