Free home energy tools
Find out what your appliances cost, plan your AC use, and compare changes before you spend. Free calculators with clear formulas and your own local electricity rate.
Calculate daily, monthly and annual electricity costs from watts, hours, quantity and your electricity rate.
Open calculator →Estimate air conditioner electricity use, monthly running cost and the savings from one fewer scheduled hour each day.
Open calculator →Estimate a monthly electricity bill with your kWh usage, local flat rate, fixed charge and tax.
Open calculator →Compare your current bill with a lower-use month or a different electricity rate, including fixed charges and tax.
Open calculator →Compare keeping an appliance with replacing it using annual kWh, purchase cost, rebates and electricity savings.
Open calculator →Use the currency and per-kWh price on your own bill.
Check the formulas, worked examples and calculation breakdown.
Calculations run on your device. Inputs stay in your browser.
Start with the appliance you use most. Enter its electrical input power, daily hours and the rate on your utility bill. Then explore your full bill, a lower-use month, or an appliance upgrade. All example rates are illustrative; no live local tariffs are supplied.
Use the energy charge per kWh on your utility bill. Fixed charges and tax belong in the bill calculator. For time-of-use or tiered rates, enter a representative blended rate.