The short answer
Divide the stated kWh per 100 cycles by 100 to obtain the corresponding per-cycle energy, then multiply by your electricity price. Annualizing uses your compatible weekly cycle count and 52 weeks. A weighted eco declaration is a test basis, rather than a promise for every programme or load.
Divide the printed energy figure by 100
kWh per 100 cycles describes energy on a stated test basis. Divide by 100 to obtain the corresponding per-cycle quantity. Then multiply by your electricity price.
The European Commission identifies the washing-machine label figure as weighted energy for the eco 40–60 programme. It is not a promise that every programme or every full load uses that amount.
A real label rather than a made-up model
Bosch’s WAN28258GB energy label shows 46 kWh/100 cycles and an 8 kg rated capacity. This GB manufacturer document demonstrates the units; use the exact model and source for your own market.
Using an illustrative £0.28/kWh and four cycles each week:
| Calculation | Result |
|---|---|
| 46 ÷ 100 | 0.46 kWh per cycle on the label basis |
| 0.46 × £0.28 | £0.1288 per cycle |
| 0.46 × 4 × 52 | 95.68 kWh per year |
| 95.68 × £0.28 | £26.79 per year, rounded |
The price and household frequency are assumptions chosen for the calculation. The energy figure is documented. Water, detergent and other costs remain separate.
Why the product sheet can show a slightly different number
The same model’s product information sheet, dated 28 November 2025, states 0.461 kWh per eco 40–60 cycle. The label’s per-100-cycle number is displayed as a whole number.
Using the product-sheet figure directly gives 95.888 kWh/year and £26.85/year with the same assumptions. The difference from the rounded-label calculation is about six pence annually. Neither calculation requires changing the tariff to make the figures agree.
Choose one source basis and retain its precision. Do not imply that 0.461 was independently measured in your home or that rounding explains every difference between documents. A different model, programme or label version can be a substantive difference.
Two equivalent calculator inputs
For the rounded label scenario, enter either:
- 46 with kWh / 100 cycles selected.
- 0.46 with kWh / cycle selected.
Both produce the same result. To use the product sheet instead, enter 0.461 with the per-cycle basis. Entering 0.461 while keeping the per-100-cycle unit would divide an already converted figure again.
A stated annual figure belongs in the annual field. It should not be copied into a per-cycle field or divided by an assumed household cycle count.
Apply your routine without rounding each load first
The displayed cost of a label-based cycle rounds to £0.13. Multiplying that rounded number by 208 cycles would give £27.04, rather than the £26.79 estimate calculated from energy.
Keep the unrounded energy and rate in the annual calculation. The monthly result is an annual average divided by 12; a busy month can differ.
If your routine includes several programmes and you have separate compatible energy measurements, model them as distinct groups. The eco label does not supply a measured value for a hotter wash or a quick programme.
Put the figure into a household decision
Open the washing-machine calculator or load the documented label example below. Use the label reader if you need help choosing the energy basis.
For different washing tasks, add separate rows in the household planner. Read the cost-per-load guide for mixed routines and the UK/EU journey before combining laundry labels from different markets.