The short answer
Choose the chilled and frozen storage capacity your household needs before comparing energy. Price each suitable solution’s compatible annual kWh at the same tariff, including additional units if needed. A smaller appliance or better class letter alone does not establish the best cost for the same storage task.
Define the storage task first
Write down the chilled and frozen storage your household needs. The EU refrigeration label shows separate compartment volumes, which helps avoid treating all combined litres as interchangeable.
Energy Saving Trust also emphasizes choosing an appropriate appliance size. A class letter is not a substitute for checking whether the appliance fits the task.
Compare whole solutions
Suppose one illustrative arrangement is a fridge-freezer using 260 kWh/year. A smaller fridge using 150 kWh/year plus a separate freezer using 180 kWh/year totals 330 kWh/year.
At €0.30/kWh:
| Arrangement | Annual energy | Annual electricity |
|---|---|---|
| One fridge-freezer | 260 kWh | €78.00 |
| Fridge plus separate freezer | 330 kWh | €99.00 |
| Difference | 70 kWh | €21.00 |
This does not rank all combined appliances above separate ones. It demonstrates why comparing the 150 kWh fridge alone would omit part of the second solution.
Do not treat kWh per litre as a complete ranking
Dividing annual energy by capacity can be a descriptive ratio. It does not resolve different proportions of frozen storage, temperature compartments, features or the amount of storage you will actually use.
A larger appliance can have an appealing per-litre ratio while still using more total kWh. If you do not need the additional capacity, the household cost is based on total energy, not the ratio.
For example, 200 kWh across 250 litres and 270 kWh across 400 litres produce different ratios, but their annual cost difference at €0.30 is still €21.
Add purchase costs on the same basis
If the second solution requires two appliances, include both purchase prices. Keep the annual figures compatible and check whether the quoted prices include the costs you intend to compare.
The comparison calculator can accept the sum of annual energy and purchase prices for a clearly defined arrangement. Make a note of the components because the tool will display one total for each option.
Open the appliance comparison calculator. Read the fridge label guide and the total-cost guide before deciding how much weight to place on the electricity difference.