Energy consumption calculator
Annual consumption is running watts times hours per day times days per year, divided by a thousand. A 150 W compressor running eight hours a day all year uses 438 kWh — which is a realistic figure for a fridge-freezer despite its 150 W plate rating.
How to estimate annual consumption
Duty cycle is what separates this page from a simple wattage multiplication. Fridges, freezers, pumps, heating and air conditioning all cycle, and the fraction of time they run swamps every other variable. A freezer in a cold garage runs a fraction as often as the same freezer in a warm kitchen. Appliance energy labels quote an annual kWh figure measured under a standard duty cycle, which is why the label number and your bill can diverge sharply — the label is a comparison between products, not a prediction about your house.
Questions
The fraction of time a device actually runs. A fridge compressor typically runs 30–40% of the time, so its annual use is far below its rating times 24 hours.