Electricity Cost Calculator

Estimate the running cost of any appliance

Enter the power rating of an appliance in watts, how many hours a day you use it, and the price you pay per kilowatt-hour (kWh). The calculator instantly shows the energy it uses and what it costs to run per day, per month, and per year. It is handy for deciding whether to replace an old fridge, leaving a heater on, running a gaming PC, or comparing a 60 W bulb with an LED.

The math is simple: energy in kWh equals watts divided by 1000, multiplied by the hours of use. So a 1000 W heater running 24 hours uses 24 kWh a day. Multiply by your price per kWh to get the cost. Monthly figures assume 30 days and yearly figures assume 365 days, so they are even, round estimates rather than a billing-exact total.

You can find the wattage on the appliance label, the power supply, or the manufacturer spec sheet. For devices that cycle on and off (like fridges or air conditioners) use the average running wattage, not the peak, and estimate the hours they actually draw power. Everything runs in your browser — no numbers are uploaded.

FAQ

Where do I find an appliance’s wattage? Check the rating label on the device, the power brick, or the manufacturer’s spec sheet. It is shown in watts (W) or sometimes as volts × amps, which multiply to give watts.

What price per kWh should I enter? Use the unit rate from your electricity bill. It is the price for one kilowatt-hour, and the cost figures are shown in whatever currency that rate is in.

Why are the monthly and yearly totals only estimates? They assume a flat 30 days per month and 365 days per year at constant use. Real bills vary with seasonal use, tiered tariffs, taxes, and standing charges.

How do I estimate cost for a device that turns on and off? Use its average running wattage and the number of hours it is actually drawing power, not the time it is plugged in.