How the estimate is calculated

Multiply watts per appliance by the quantity, daily hours, and days. Divide by 1,000 to convert watt-hours to kilowatt-hours, then multiply by the electricity rate. A 1,500-watt heater used two hours daily for 30 days consumes 90 kWh.

Rated power versus actual use

Nameplate wattage may be a maximum rather than an average. Thermostats, compressors, chargers, and variable-speed devices cycle or change load. Actual energy measured over a representative period usually gives a better estimate.

Understanding the tariff

Enter the energy price for one kWh. Utility bills may also contain fixed fees, taxes, tiered rates, time-of-use prices, demand charges, credits, or minimum charges that this calculator does not include.

Use the Power Converter when a rating is not stated in watts, and the Energy Converter for kWh and joules.

This is a planning estimate, not a prediction of the full utility bill. Follow electrical safety instructions and do not measure circuits with unsuitable equipment.