How to Calculate What an Appliance Costs to Run
The running cost of any appliance comes down to its wattage, how long it runs, and your tariff. Here is the calculation behind your bill.
What is the Electricity Cost Calculator?
The calculator multiplies watts by hours used per day and days in the period, then divides by 1000 to convert watt-hours into kilowatt-hours. Multiplying those kilowatt-hours by your price per kilowatt-hour gives the running cost for the period.
How to use it
- Enter the appliance's power in watts.
- Enter how many hours per day it runs and how many days to cover.
- Enter your electricity price per kWh and press Calculate.
Worked example
100 watts, 5 hours per day, 30 days, price 0.25 per kWh: the tool gives 15 kWh and a cost of 3.75.
How much does a 100-watt appliance cost to run 5 hours a day for 30 days at 0.25 per kWh?
It uses 15 kWh, because 100 watts times 5 hours times 30 days divided by 1000 is 15, and at 0.25 per kWh that costs 3.75. The same method works for anything from a light bulb to a washing machine.
Frequently asked questions
Where do I find the wattage?
Check the label on the appliance or its manual. If it only lists amps and volts, multiply them together to get watts.
What is a kilowatt-hour?
It is the energy used by a 1000-watt appliance running for one hour, and it is the unit most electricity bills charge by.