Calculate appliance cost from an energy label

First identify what the label actually reports

Three label figures look similar but answer different questions. Rated watts describe electrical input at a particular operating state. Kilowatt-hours per cycle describe one programme or use. Annual kWh is a standardized estimate based on a defined test pattern. Write down the number, unit, test programme, and reference period before calculating anything.

Do not multiply annual kWh by daily runtime. The runtime assumption is already embedded in the annual figure. Likewise, do not treat kWh per cycle as kW: energy and power are related, but they are not interchangeable.

Use annual kWh when the appliance cycles

For refrigerators, freezers, heat-pump dryers, and other cycling equipment, an annual energy figure is often more useful than maximum input power. It already captures a standardized pattern of compressor, heater, fan, pump, and standby operation.

Your home may differ from the test. Ambient temperature, programme choice, load size, door opening, ventilation, and maintenance can move actual consumption above or below the label.

Use kWh per cycle for washers and dryers

Multiply the programme energy by the number of cycles you expect to run. If your label gives 0.72 kWh for a programme and you run four cycles each week, the annual estimate is 0.72 × 4 × 52 = 149.8 kWh.

Use the programme you actually select. An eco, hot, quick, or intensive programme can have a different energy profile, and a washer-dryer adds a separate drying stage.

Use rated watts only with active time

If the only usable figure is watts, convert it to kilowatts and multiply by the time the appliance actively draws that power. A 2,000 W heater running at full power for 90 minutes consumes 3 kWh. A thermostat-controlled heater scheduled for 90 minutes may consume less because the element cycles off.

Adjust the label without pretending it is measured

Keep the label result as a baseline, then make one explicit adjustment at a time. For example, scale per-cycle energy by your cycle count, or compare the standardized annual figure with a seven-day meter reading. Mark the result as label-derived until real energy has been observed. A precise currency figure does not make the underlying consumption precise.

A practical decision rule

Use annual kWh to compare like-for-like models under the same label regime. Use your tariff to translate the difference into annual money. If the purchase decision depends on a small projected saving, verify the existing appliance with a meter before replacing it. Manufacturing cost, repairability, capacity, and remaining life belong in the decision even though they are outside the electricity calculation.