How the Electricity Cost Calculator Works
The calculator multiplies the power rating by the number of appliances and hours used each day, multiplies by the billing-period days, and converts watt-hours to kilowatt-hours. It then multiplies energy use by the rate you enter.
Formula and method
Energy (kWh) = watts × quantity × hours per day × days ÷ 1,000. Estimated cost = energy (kWh) × electricity price per kWh.
Tips for better estimates
Use the appliance label or a plug-in energy meter for wattage. Enter realistic daily usage and the energy-only rate from your bill; some bills have separate delivery charges and taxes.
Important limitations
The estimate excludes standby power, variable tariffs, time-of-use pricing, fixed charges, demand charges, taxes, and other bill components. Actual consumption may differ from the rated wattage.