Electricity bills often arrive only once a year, sometimes with an unwelcome surprise. Knowing how the charges are calculated helps you check a bill, compare tariffs and identify energy-hungry appliances.
What makes up an electricity bill?
- Unit price: the price for each kilowatt-hour (kWh) you use.
- Standing charge: a fixed monthly or annual amount, regardless of usage.
Formula: Annual cost = annual usage (kWh) × unit price + annual standing charge.
Worked example
The prices below are examples only. Use the figures in your own contract or bill.
| Item | Value |
|---|---|
| Annual usage | 2,500 kWh |
| Unit price | €0.30 per kWh |
| Standing charge | €12 per month = €144 per year |
| Usage charge | 2,500 × €0.30 = €750 |
| Annual total | €750 + €144 = €894 |
Enter your own figures in the electricity cost calculator to see estimated monthly and annual costs.
Estimate an appliance’s electricity use
Use this formula: power in watts ÷ 1,000 × hours of use = kWh.
For example, a 1,000-watt appliance used for two hours per day consumes 2 kWh per day, or 730 kWh per year. At €0.30 per kWh, that is €219 a year for this appliance alone.
Where you may be able to save
- Switch appliances fully off instead of leaving them on standby.
- Check energy-efficiency labels when replacing equipment.
- Run washing machines and dishwashers with full loads.
- Review older appliances that run continuously, such as refrigerators.
- Compare tariffs regularly and check notice periods before switching.
Remember heating
Electric heating is included in your electricity use. For gas, oil or district heating, use the heating cost calculator for a separate estimate.
All figures above are examples. Actual prices vary by supplier, region and contract.