The formula, made clear.
Energy in kWh = watts ÷ 1,000 × hours per day × days. Cost = energy × electricity price per kWh.
Actual bills can include tiered tariffs, taxes, fixed charges and appliance cycling, so use the result as an estimate.
HOME ENERGY TOOL
Electricity Cost Calculator
Estimate how much electricity an appliance uses and what it may cost to run over a chosen period.
Estimated electricity cost24.3135 kWh over 30 days · 0.81 per day
When to use this calculator
Estimate the running cost of an air conditioner, heater, computer or other appliance before it affects your utility budget.
See the calculation in context
A 1,500-watt appliance used three hours daily for 30 days consumes 135 kWh. At 0.18 per kWh, the estimated cost is 24.30.
Frequently asked questions
Where do I find appliance watts?
Check the rating label, manual or manufacturer's specification.
Why can my bill differ?
Appliances may cycle on and off, and providers may add tiers, taxes and fixed charges.