Electricity cost calculator
List your appliances, their power and the hours they run, and see how many kilowatt-hours they use in a month. Add your tariff to see the cost.
Appliances
Appliance, power in watts, hours of use per day, and how many you have.
How the estimate works
Electricity is billed in kilowatt-hours (kWh). One kWh is 1,000 watts used for one hour. For each appliance the tool multiplies watts by hours per day, by quantity, by the number of days, and divides by 1,000. Multiply the total kWh by your tariff to get the cost.
Worked example
A 1,500 W split air conditioner running 8 hours a day uses 12 kWh a day, or 360 kWh over 30 days. Two 75 W ceiling fans running 10 hours a day use 45 kWh in the same month. At a tariff of 0.30 per kWh, the AC costs about 108 and the fans about 13.50.
Good to know
- Wattages in the preset list are typical values. Check the label on your own appliance.
- For a refrigerator or an air conditioner that cycles on and off, use the average running time, not 24 hours.
- Utilities may use tiered tariffs, fuel surcharges or fixed fees, so an actual bill can differ. Use your latest bill to find your real tariff.
- This is a planning tool. Learn how to read a bill in the electricity bill guide.
Frequently asked questions
What is a kWh?
A kilowatt-hour is the energy used by a 1,000-watt appliance running for one hour.
Where do I find my tariff?
On your electricity bill, usually as a rate per kWh. If there are slabs, use the rate for the slab where most of your use falls.
How do I find an appliance’s watts?
Look for the rating label on the back or bottom of the appliance, or in its manual. Where only amps and volts are given, multiply them to get watts.