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Tools / Energy / Electricity Cost Calculator

See what individual appliances and devices cost to run from their wattage, hours of use, and your electricity unit rate.

Use it to estimate running cost per day, month, or year. It is for appliance costs rather than a full household electricity bill.

p
Watts

kW

Hours

kWh
Cost per 10 mins:-
Cost per day:-
Cost per month:-
Cost per year:-
Total cost per day:
£0.00
Total cost per month:
£0.00
Total cost per year:
£0.00

* The results provided by this calculator are estimations only. Actual figures may vary due to differences in rates or usage. View full disclaimer

Total cost per day: £0.00

How is electricity cost calculated?

To calculate how much a device or appliance costs to run, simply multiply the amount of energy used (kWh) by the unit cost of one kWh.

For example

If an oven uses 2000 watts of electricity, or 2 kW, and you use the oven for 2 hours, then you will have used 4kWh. If the unit cost of 1 kWh is 35p for example, multiply 35p by 4.

£0.35 x 4 = £1.40

Frequently Asked Questions

What if my appliance shows watts rather than kWh?
Convert watts into kilowatts by dividing by 1000, then multiply by the number of hours used. A 2000W heater is 2 kW, so if you use it for 3 hours that is 6 kWh. You then multiply those 6 kWh by your electricity unit rate to get the running cost.
What is a kWh and how does it affect the result?
A kWh (kilowatt-hour) is a unit of electricity use. If a 1 kW appliance runs for 1 hour, that is 1 kWh. The more kWh an appliance uses, the higher the running cost because your unit rate is charged per kWh and feeds into the total cost results.
Does the result include the standing charge?
No. This calculator shows appliance running cost from electricity used only. It does not add the daily standing charge that appears on a full electricity bill. If you want a bill estimate with meter readings, use the Electricity Bill Calculator instead.
What electricity unit rate should I use?
Use the unit rate shown on your electricity bill if you have it, because that reflects your actual tariff. If you do not know it yet, a regional Ofgem price-cap rate is a reasonable estimate to start with, but your supplier's rate may be higher or lower.
Can I use this as proof in a dispute with my energy provider?
No. This calculator is for personal estimation only and should not be relied on as evidence in a billing dispute. If you believe your bill is wrong, contact your supplier directly with your actual meter readings. If that doesn't resolve it, you can escalate through Ofgem's complaints process or the Energy Ombudsman.