WhatItCosts

Electricity usage calculator

Find out what any appliance costs to run. Enter its watts, how long you use it and your electricity price.

How do you know the power?

Look for a W or watts figure on the label or power adapter.

30 minutes is 0.5.

Lower this for appliances that cycle on and off, such as heaters and fridges. Leave at 100 if it runs at full power the whole time.

This starts as an example price. Replace it with the rate on your bill. How to find your rate.

kilowatt-hours per month

PeriodkWhCost

Calculators for common appliances

Pick an appliance to start with typical wattage and realistic settings already filled in.

Lighting

Electronics and office

Heating and cooling

Kitchen

Laundry and cleaning

Home and vehicles

How the calculation works

Electricity is billed in kilowatt-hours (kWh). One kWh is 1,000 watts used for one hour. The calculator multiplies the appliance's watts by the hours you use it, divides by 1,000 to get kWh, then multiplies by your price per kWh.

Cost = watts × hours ÷ 1,000 × price per kWh

Appliances such as fridges, heaters and air conditioners switch on and off to hold a temperature. For those, lower the "time at full power" setting so the result matches real use.

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