Enter an appliance’s wattage, daily hours and your electricity rate to see what it costs per day, month and year.
What this calculator does
Every appliance’s running cost comes from the same three numbers: its power draw in watts, how long it runs, and what your utility charges per kilowatt-hour. This calculator multiplies them out and shows the cost per day, per 30-day month and per year — the yearly figure is usually the eye-opener, because always-on devices compound quietly.
How to use it
- Enter the appliance’s wattage (from its label or plate).
- Enter the hours it runs per day.
- Enter your rate per kWh from your electricity bill.
The formula
A worked example
A 100-watt device running 6 hours a day uses 0.6 kWh daily. At $0.17 per kWh that is about $0.10 a day — harmless — but $3.06 a month and $37.23 a year. Run the same numbers for a 1,500-watt space heater at 6 hours and the year lands near $560, which is why heaters and air conditioners dominate bills while phone chargers round to nothing.