Electricity Cost Calculator

Understanding Your Electricity Costs

Electricity in the UK is priced per kilowatt-hour (kWh). As of 2025, the Ofgem energy price cap sets the unit rate at approximately 24.5p per kWh, though your actual rate may vary depending on your tariff and supplier. A kilowatt-hour means using 1,000 watts of power for one hour. So a 100W TV running for 10 hours uses 1 kWh and costs around 24.5p.

Peak and off-peak pricing is becoming more common with smart meters and time-of-use tariffs like Octopus Agile. Peak hours are typically 4pm to 7pm when demand is highest and electricity can cost significantly more. Off-peak hours, usually overnight between 12am and 6am, can be much cheaper. If you have a smart meter, you can track exactly when you use the most energy and shift heavy usage like running the washing machine or dishwasher to cheaper off-peak periods.

To reduce your electricity bill, focus on the biggest consumers first. Electric showers (8,500W), ovens (2,000W), and tumble dryers (2,500W) are the most expensive appliances to run. Switching to LED bulbs saves around 80% compared to halogen. Turning off standby devices can save the average UK household around 50 pounds per year. A smart meter gives you real-time visibility of your spending and many energy suppliers offer them free of charge. Consider whether a fixed-rate or variable tariff suits you better, and use comparison sites regularly. The average UK household uses around 2,700 kWh per year, costing approximately 660 pounds at current rates.