In an illustrative UK calculation, 0.6 kWh at 30p/kWh plus 50 litres at £3 per cubic metre costs 33p per wash. These are assumed inputs. For your own result, multiply cycle electricity and metered water by the matching tariffs; add drying separately without counting it twice.
See the 33p wash-cost example ↓
Open laundry running cost calculatorIn this guide
18p electricity + 15p metered water = 33p
Five washes a week: £1.65. Over 52 weeks: £85.80 before drying. Multiply the unrounded per-load value when planning a schedule.
Collect four figures before comparing programmes
You need electricity used per wash, the electricity price per kWh, water used per wash and the applicable water tariff. Use measured consumption where available, or identify the exact published programme and its test basis. Record the tariff date and keep every price in one currency.
Energy Saving Trust explains that current UK washing-machine labels show energy per 100 eco washes. Divide a stated per-100-cycle figure by 100 before using it as a per-cycle input. Do not enter the label’s whole number as one wash, or assume its tested eco figure measures a different programme you routinely select.
Read the evidence: Energy Saving Trust home appliance energy labels
The cost-per-wash formula, with a worked example
For water priced per 1,000 litres, use: wash cost = (wash kWh × electricity tariff) + (litres ÷ 1,000 × water tariff). If your water bill includes a relevant metered wastewater charge, account for the applicable charge in the tariff you enter and keep its basis clear.
In a hypothetical example, a wash uses 0.8 kWh at 0.30 per kWh and 50 litres at 2.00 per 1,000 litres. Electricity is 0.24; water is 0.10. The total is 0.34 in the chosen currency. At five such loads each week, the estimate is 1.70 per week and 88.40 over 52 weeks. These invented inputs illustrate arithmetic, not current tariffs or measured appliance performance.
Add electric drying without counting it twice
A separate electric dryer using an illustrative 1.5 kWh at 0.30 per kWh adds 0.45 for that drying load. Added to the 0.34 example wash, the combined amount is 0.79. If all five weekly loads use that dryer cycle, the estimate becomes 3.95 per week and 205.40 over 52 weeks.
A washer-dryer’s published combined wash-and-dry figure already includes both stages. Energy Saving Trust describes the separate label entries. Do not enter a combined figure as wash-only energy and then add the same drying again. Use wash-only data plus genuinely separate electric drying, or keep a complete combined cycle as one scenario with no duplicated dryer input.
Read the evidence: Energy Saving Trust home appliance energy labels
When you dry only some loads
The calculator applies its entered dryer use to each planned wash. To compare a mixed routine, calculate wash-only costs for all washes and add the separately calculated drying cost only for the loads you actually machine dry. Keep the schedule beside the result so you can reproduce it.
For the same illustrative values, five washes cost 1.70 per week. Drying two loads adds 2 × 0.45 = 0.90, making 2.60 per week or 135.20 over 52 weeks. This calculation covers electric dryer consumption only; it does not model gas drying or infer a drying duration.
Keep units and exclusions visible
Choose litres or US gallons and use the matching water tariff unit. A US gallon is not an imperial gallon. Re-enter values when changing units rather than carrying an unchanged number across. Selecting a currency changes the display; it does not convert tariffs or apply an exchange rate.
This comparison excludes fixed utility charges, detergent, maintenance and appliance purchase costs. Unmetered water charges cannot be treated as a measured per-load saving. Avoid calling the result your total laundry bill: it is the cost of the consumption and rates you supplied.
- Compare like-for-like programmes and load schedules.
- Record whether consumption is measured or label-based.
- Separate wash-only and drying assumptions.
- Keep omitted costs beside any claimed saving.
A UK example from one wash to a weekly budget
Assume, for this example only, 0.6 kWh per wash, 50 litres of metered water, electricity at £0.30/kWh and the applicable combined volumetric water charge at £3 per cubic metre. Electricity is £0.18 and water is £0.15, giving £0.33 per wash. Five washes per week cost £1.65; multiplying by 52 gives £85.80 annually before optional drying.
Those tariffs and consumption figures are editable assumptions, not current UK averages. Use the units and water/sewer charging basis on your own bill. An unmetered water bill needs separate treatment; do not invent a per-litre marginal charge. Standing charges are not caused anew by each wash.
| Example component | Calculation | Cost |
|---|---|---|
| Electricity | 0.6 × £0.30 | £0.18 |
| Metered water | 50 ÷ 1,000 × £3 | £0.15 |
| One wash | £0.18 + £0.15 | £0.33 |
| Five weekly washes | £0.33 × 5 | £1.65 |
Read the evidence: Energy Saving Trust home appliance energy labels
Check your calculation
How do I turn energy per 100 washes into energy per wash?
Divide the stated figure by 100, keeping the programme and label basis clear. An illustrative 50 kWh per 100 washes becomes 0.5 kWh per wash. That describes the stated test basis; it is not a measurement of every programme you might select.
Does the result include detergent and standing charges?
No. This calculator covers entered metered electricity and water, with optional electric dryer use. Detergent, fixed charges, repairs, servicing and purchase costs need a separate comparison if you want to estimate the wider cost of doing laundry.
Can I use a washer-dryer’s combined energy figure?
Keep its basis explicit and count it once. A combined wash-and-dry figure is not wash-only energy. Do not add the same drying stage again through the optional dryer input; compare a complete combined scenario or use appropriately separate wash-only and dryer data.
Does a different currency selection change my prices?
No. Enter electricity and water prices in the selected currency yourself. There is no foreign-exchange conversion. For a useful comparison, use consistent units, tariffs and included expenses throughout.
Sources and scope
Cost examples use stated tariffs and consumption assumptions, not a current bill or market-price quote. Use your own tariff and appliance programme data; exact product care instructions still determine the permitted wash or dry method. Report a correction with the page and supporting source.