Electricity cost calculator
Enter an appliance's wattage, how long it runs and your unit rate. Get kWh, period cost and a 30-day estimate instantly.
Electricity cost formula
Electrical power is usually shown in watts (W). Bills charge for energy in kilowatt-hours (kWh), so first convert watts to kilowatts and multiply by time.
Cost: kWh × price per kWh = usage cost
Worked example
A 1,000 W appliance running for 2 hours uses 2 kWh. If your unit price is €0.30/kWh, the usage cost is €0.60. Repeat the same use on 30 days and the usage portion totals €18.00.
What this estimate does not include
Electricity bills may contain fixed charges, taxes, network charges or time-of-use prices. If those costs are not already included in the unit rate you enter, they are outside this appliance-level estimate.
Frequently asked questions
What if my appliance changes power while running?
Use average measured power or measured kWh over a typical session. Maximum rated power is useful as a conservative estimate but may not reflect cycling or variable loads.
Can I use this with pounds, euros or other European currencies?
Yes. The calculation is currency-neutral; the selector only changes how the result is displayed.
Is 1,000 watts the same as 1 kWh?
No. 1,000 watts is power. A 1,000 W device running for one hour uses 1 kWh of energy.
Why a single "European electricity price" does not exist
Household electricity prices vary enormously across Europe, shaped by each country's generation mix, network costs, taxation and support schemes. A household in France, where nuclear generation dominates, can pay a meaningfully different unit rate to one in Germany or Italy, and even within a single country, tariffs vary by supplier, contract type, time-of-use structure and region. That is why this calculator asks for your own price per kWh rather than assuming a continental average — any single figure quoted as "the European price" would be misleading for the majority of readers.
Using this calculator for multiple appliances
The fastest way to build a realistic picture of your electricity bill is to run this calculator once per significant appliance, using its own wattage and typical daily use, and add the results together. Large, long-running loads — a fridge running 24 hours a day, a tumble dryer or an electric shower — usually contribute far more to a bill than small but power-hungry devices used briefly, like a kettle or toaster. Our dedicated appliance calculators, listed below, provide realistic default wattages for each of these common cases.
Example monthly costs by appliance category
| Appliance type | Typical power | Typical use | Approx. monthly cost* |
|---|---|---|---|
| Refrigerator (always on) | 120 W avg | 24 h/day | €26 |
| Electric heater (winter) | 2,000 W | 4 h/day | €72 |
| Washing machine | 1,200 W avg | ~5 loads/week | €7 |
| Gaming PC | 350 W | 4 h/day | €13 |
| Air fryer | 1,500 W | 25 min/day | €2 |
*Illustrative figures at €0.30/kWh. Use the calculator above and our appliance-specific pages for numbers based on your own equipment and tariff.
More frequently asked questions
Why does my actual bill not match this calculator exactly?
This tool estimates usage cost for one appliance or scenario at a time. Your bill also totals every other appliance in the home, plus standing charges, taxes and network fees that are separate from appliance-level usage.
Where do I find my own price per kWh?
Check a recent bill, your supplier's online account, or your contract documentation. Many European suppliers also show live unit rates in their app, particularly for time-of-use or dynamic tariffs.
