Energy Labels and Running Costs: What Appliances Really Cost You

The energy label is the most useful piece of information attached to a major appliance, and one of the most widely misread. It is not a forecast of what the machine will cost you. It is a standardised comparison, produced under conditions almost nobody replicates at home — and once you know that, it becomes genuinely powerful.

This guide explains what each element means, how to convert the figures into money using your own tariff, and how to work out whether a more efficient model repays its premium.

How to read the current UK energy label

The label uses a rescaled A to G colour scale, introduced to replace the older A+ to A+++ system that had bunched almost every appliance at the top. The rescale deliberately left room above the current best, so a machine rated C on the current scale may be highly efficient — and a class from an old label cannot be compared with one from a new label.

Beyond the letter, the label carries a QR code linking to a product database entry, the energy consumption figure, and a set of category-specific measurements. On washing machines and washer-dryers you will find capacity, programme duration, water consumption in litres per cycle, a spin-drying efficiency class, and airborne noise in dB(A) with a noise class from A to D. Dishwashers show place settings, water per cycle, programme duration and the same noise information. Refrigeration shows compartment volumes and noise.

The noise class matters more than buyers expect in an open-plan kitchen, and it is one of the few comparable acoustic figures published anywhere — a point picked up in how to choose kitchen appliances.

Why the label’s annual figure rarely matches your bill

Every headline consumption figure is the output of a defined test programme. For washing machines and washer-dryers it is the standard eco programme measured across a combination of full and partial loads; for dishwashers it is the eco programme. Those cycles are long and run at low temperatures, because that is how efficiency is achieved.

Most households do not use them. Quick washes, hotter programmes, half loads, intensive dishwasher cycles and the drying stage on a washer-dryer all consume more than the tested cycle, sometimes considerably more. For refrigeration, the test assumes a defined ambient temperature and no door openings; a fridge in a warm kitchen, opened frequently, works harder than the tested one.

None of this makes the label dishonest. Every manufacturer is measured the same way, which is exactly what makes the comparison valid. It simply means the number answers “which machine uses less?” and not “what will this cost me?”

Turning kWh into pounds, step by step

The arithmetic is simple, and the only figure you must supply yourself is the unit rate from your own bill.

1. Find your unit rate in pence per kWh, from your tariff or a recent statement. Do not use a national average — rates vary by tariff, meter type and region, and the average is nobody’s actual price.
2. Scale the label figure to your usage. For a per-100-cycles figure, divide by 100 to get the consumption of one cycle, then multiply by the number of cycles you run in a year. For an annual refrigeration figure, use it as it stands.
3. Multiply by the unit rate and divide by 100 to convert pence to pounds.
4. Add a realism margin if you do not use the eco programme, and note that this is an adjustment you are making rather than a published figure.

Standby, cycles and how usage patterns change the maths

Three usage variables move the result more than the class letter does.

Cycle count. Running fewer, fuller loads reduces consumption more reliably than upgrading a class. A household that halves its number of washes has done more than the gap between two adjacent classes typically delivers.

Programme choice. The eco programme is slow because low temperature and long duration is the efficient trade. Using quick or hot cycles by default moves your real consumption away from the label in the direction of the older, less efficient machine you replaced.

Standby. Small for most appliances individually, but it applies continuously and across everything in the house. It matters most for devices that are never switched off and least for machines used in discrete cycles.

For anything that heats, the temperature setting dominates. Heating water is where the energy goes, which is why washing cooler is the single largest lever available to most households.

The payback calculation for an efficient model

The question is not which model is cheaper to run, but whether the saving repays the premium within the time you will own it.

1. Price difference between the two models, including any delivery or installation difference.
2. Annual saving: calculate the annual running cost of each using the method above, and subtract.
3. Payback period = price difference ÷ annual saving.
4. Compare with your intended ownership period. If payback exceeds it, the premium does not repay in your hands, whatever it would do in someone else’s.

Two adjustments make it honest. Use your actual cycle count, not a manufacturer’s assumption. And remember the calculation only counts energy — if the efficient model also uses less water, is quieter, or has better parts availability, those are separate reasons that belong in the whole-life view in total cost of ownership. Where an appliance is used rarely, the same logic pushes towards the cheaper machine, as in cost per use.

Water use and detergent as hidden lines

Water consumption appears on washing machine and dishwasher labels in litres per cycle, and it is easy to ignore because it is not converted into money anywhere. On a metered supply it should be: multiply litres per cycle by cycles per year, convert to cubic metres, and apply your water and wastewater rates. On an unmetered supply it changes nothing financially, which is worth knowing before paying a premium for it.

Detergent and consumables are the line nobody prints. Dishwasher tablets, salt, rinse aid, filters and descaler recur for as long as you own the machine, and where a manufacturer ties you to proprietary supplies the annual cost can exceed the electricity. Price a year’s supply before buying, not after.

Maintenance belongs here too: a machine kept clean and descaled runs closer to its tested figures, and neglected wear parts push consumption up long before they fail — the link between running cost and lifespan explored in how long should things actually last.

Categories where efficiency matters most

Efficiency pays in proportion to hours of operation and to how much heating or cooling is involved.

Highest return: refrigeration, because it runs continuously for its entire life; tumble dryers and washer-dryers, because they heat air for long periods; and anything used daily in a large household.

Moderate return: washing machines and dishwashers, where the class difference is real but the programme you choose and the number of cycles you run matter comparably.

Low return: appliances used briefly or occasionally, where the energy consumed is small in absolute terms regardless of class, and where build quality and repairability are better places to spend the premium — the judgement covered in how to judge product quality online.

When should efficiency change the purchase?

Our verdict

Energy labels are disciplined comparison inputs, not predictions of your bill. Recalculate from your usage and tariff, keep non-energy benefits separate and avoid claiming precision that the standardised test cannot provide.

For a worked appliance-specific ownership comparison, read our Coffee machine running costs: pods, beans, milk and maintenance.

For drying laundry, compare the technology and installation requirements before estimating bills with our Tumble dryer types: heat pump, condenser and vented costs compared.

Before applying a running-cost estimate to room heating, check suitability and safety with our Portable heater buying guide: power, controls, safety and running cost.