How much does it cost to leave an appliance on?

Learn how to convert watts, usage hours and price per kWh into an estimated monthly cost.

The basic formula

Power in watts ÷ 1000 × hours of use × days × price per kWh. It provides a quick estimate, although a real electricity bill can include other charges.

Example: a 1,000 W appliance used 2 hours a day for 30 days consumes about 60 kWh. At €0.18/kWh, that is €10.80.

Practical tip

Rated power does not always mean constant consumption. Refrigerators, climate-control equipment and other appliances can operate in cycles. Measuring actual use over several days is more useful.

Conclusion

At AhorraEnCasa we separate calculation, measurement and purchasing. A useful recommendation should explain what problem it solves and its limitations.