About electricity cost
This calculator estimates how much an appliance costs to run, from its power in watts, how many hours a day you use it, and your electricity rate per kilowatt-hour (kWh). It shows the cost per day, month and year. It runs in your browser.
How Electricity Cost works
How to use it
- Enter the appliance's power in watts.
- Enter hours used per day and your kWh rate.
- See the running cost per day, month and year.
How it works
Energy used per day = watts ÷ 1000 × hours (in kWh). Cost = that energy × your rate. Monthly uses an average 30.44 days and yearly uses 365 days.
Common uses
- Find an appliance running cost
- Estimate energy bills
- Compare appliance efficiency
- Budget for a heater or AC
- Work out cost per kWh use
- Decide whether to upgrade
- Check standby costs
- Plan energy savings
Frequently asked questions
How do I work out running cost?
Enter watts, hours per day and your kWh rate.
Where do I find my kWh rate?
On your electricity bill — cost per kilowatt-hour.
How is monthly cost found?
Daily cost × 30.44 (average days per month).
Is my data uploaded?
No — it calculates in your browser.
What if I do not know the wattage?
Check the appliance label or its manual.
Does it include standing charges?
No — it is the usage cost only.
Is it free?
Yes — completely free with no sign-up.