Electricity Cost Calculator
Find out what heaters, lights, computers and other appliances cost to run, from their wattage, hours of use and your electricity price.
Result
Add appliances to estimate running costs.
How to use this calculator
- Enter your electricity price per kWh from your bill.
- Add each appliance with its watts, hours used per day, how many you have and days per week.
Formula
kWh per day = watts × hours × quantity ÷ 1,000 × (days per week ÷ 7). Cost = kWh × price. A month is 365.25 ÷ 12 days.
Worked example
A 1,000 W heater for 2 hours
Uses 2 kWh a day; at 0.15 per kWh that is 0.30 a day and about 109.58 a year.
Assumptions and limitations
- Everything runs in your browser; nothing you enter is uploaded or stored.
- The power on a label is usually the maximum; appliances with thermostats or standby modes use less on average.
Frequently asked questions
Where do I find the wattage?
On the appliance’s label or manual. A plug-in energy meter gives the most accurate real-world figure.
What is a kWh?
A kilowatt-hour: the energy used by a 1,000-watt appliance running for one hour. Your bill charges per kWh.