ToolnozaElectricity cost formula
Energy cost = electricity used in kWh × price per kWh. For an appliance rated in watts, kWh = watts ÷ 1,000 × hours used. Multiply the result by the tariff that applies to that usage period.
Example: a 60 W lamp
A 60 W lamp used for 5 hours a day over 30 days consumes 60 ÷ 1,000 × 5 × 30 = 9 kWh. At $0.16 per kWh, its estimated energy charge is 9 × $0.16 = $1.44. This example excludes fixed fees and taxes.
Use the bill rate that applies
Check whether your utility uses time-of-use prices, tiered rates or separate delivery charges. For a whole bill, use the billed kWh and the matching energy rate; add fixed charges and taxes separately. Actual bills can include fees that a simple kWh estimate does not model.
Frequently asked questions
Does the result equal my full bill? No, unless all applicable fees and taxes are included. How do I convert watts to kWh? Divide watts by 1,000, then multiply by hours. Should I use the advertised rate? Use the rate and period shown on your bill.