DIY Cost Tools
Electricity Cost Calculator
Estimate the daily, monthly, and annual electricity used by an appliance from watts, operating time, and your utility rate.
How this calculator works
Kilowatt-hours = watts ÷ 1,000 × hours used. Cost = kilowatt-hours × your electricity rate.
How the estimate works: The calculator uses your measurements, unit conversions, waste allowance, and product coverage to create a planning quantity. Review the formula shown above, then read the matching guide below before ordering. See How Our Calculators Work for assumptions and limitations.
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These practical options match the work estimated by this calculator. Verify compatibility, specifications, and the current price before purchasing.
These consumer devices are intended for appropriate plug-in loads. Do not open electrical panels or work on energized wiring unless qualified. Read our advertising disclosure.
Finding the right inputs
Look for the appliance wattage on its label or manual. Devices with thermostats, compressors, variable-speed motors, or standby modes do not draw their maximum wattage continuously, so a plug-in energy meter can provide a better real-world average.
Understanding your bill
Enter the energy rate shown on your bill in dollars per kilowatt-hour. Taxes, demand charges, tiered pricing, time-of-use rates, and fixed service fees are not included. The result estimates the appliance’s energy charge rather than your complete utility bill.
Appliance electricity example
A 1,500-watt space heater used 4 hours per day for 30 days consumes 180 kilowatt-hours: 1.5 kilowatts × 4 hours × 30 days. At $0.16 per kilowatt-hour, the energy portion is $28.80. The utility bill may also include fixed charges, taxes, demand charges, time-of-use rates, or tiered pricing that this simple energy estimate does not include.
Use measured power when possible
Nameplate wattage may be a maximum rather than an average. Refrigerators, air conditioners, pumps, and other cycling equipment do not draw full rated power continuously. Use a plug-in meter or manufacturer energy data when appropriate, and calculate standby use separately. For 240-volt, hardwired, or high-current equipment, use qualified help and never improvise unsafe measurements.