Dishwasher Running Cost Calculator
Estimate the electricity, water and detergent cost of using a dishwasher. Compare eco, auto and intensive cycles, add weekly use, and see whether a full load habit changes the monthly bill.
Cycle and Tariff Inputs
Estimated Cost
The result uses 5 cycles per week, 0.85 kWh per cycle and excludes the standing charge.
This result is built around cycle behaviour, not just appliance wattage. It separates energy, water and detergent so you can see whether fewer cycles, a different programme or cheaper wash products would change the bill most.
What This Dishwasher Cost Estimate Includes
Energy
The energy line covers the electricity used by heating water, running the pump and drying dishes. Heated drying can add a noticeable amount, so the calculator keeps it as a separate option.
Water
The water line uses litres per cycle and a metered pence-per-litre rate. If you are not on a water meter, this line is still useful for comparison but will not change your bill directly.
Products
Detergent tablets, powder, salt and rinse aid are often missed in appliance comparisons. Add the real cost per wash if premium tablets make up a large part of the total.
How to Use the Calculator
Start with the kWh per cycle. The best number is from the appliance manual, the energy label product sheet or a plug-in meter. If you only have the annual label figure, divide it by the stated number of cycles on the label. Eco programmes often use less energy but take longer. Intensive programmes can use more heat and water, especially for pans, baked-on food and hygiene-style washes.
Next, enter cycles per week. A household running seven half-empty washes may spend more than a household running four full loads. The tool is designed around cycle count because most dishwashers use broadly similar energy once a programme starts. If your machine has a half-load option, use the manual figure for that programme rather than assuming it halves the cost.
Finally, add detergent and drying. A cheap cycle can become less cheap if every wash uses an expensive tablet and a heated dry. If you open the door at the end of the cycle or use an air-dry option, select air dry. If your kitchen needs the cupboard-dry result quickly, use the heated dry option and compare the extra monthly cost.
Formula and Method
cycle energy cost = cycle kWh x electricity pence per kWh / 100
heated dry cost = heated dry kWh x electricity pence per kWh / 100
cycle water cost = litres per cycle x water pence per litre / 100
cost per cycle = energy cost + heated dry cost + water cost + detergent cost
weekly cost = cost per cycle x cycles per week
monthly cost = weekly cost x 52 / 12
annual cost = weekly cost x 52 + included standing charge
The standing charge is optional because most homes pay it whether the dishwasher runs or not. Include it only when costing a separate supply, short-let property or appliance-only comparison where fixed daily charges are part of the decision.
Programme Comparison Guide
| Programme | Typical reason to use it | Cost pattern | Practical note |
|---|---|---|---|
| Eco | Normal daily dishes with enough time for a longer wash. | Usually lowest energy, often longer run time. | Longer time does not always mean higher cost because water is heated more gently. |
| Auto or sensor | Mixed loads where the machine can adjust wash intensity. | Varies by soil level. | Good if the household load changes from day to day. |
| Intensive | Pans, roasting trays and dried-on food. | Higher water temperature and higher energy use. | Scrape food first; avoid rinsing everything under hot tap water. |
| Quick wash | Light soil where dishes are needed soon. | Can use more energy than expected if it heats quickly. | Check the manual rather than assuming quick means cheap. |
| Rinse only | Holding dishes before a full wash. | Low energy, some water use. | Useful only if it prevents smells or dried-on food before a full load. |
Ways to Read the Result
- Per cycle: Best for comparing eco, auto, intensive and quick wash choices.
- Weekly: Best for changing habits, such as waiting for a full load or running after an Economy 7 off-peak period.
- Annual: Best for appliance replacement decisions, especially when comparing an older machine with a newer label figure.
- Water litres: Useful when a home is metered, has a water-saving target or compares dishwasher use with hand washing.
Worked Example
A household runs five eco cycles per week. The manual lists 0.85 kWh and 9.5 litres per cycle. With electricity at 24.67p/kWh, energy costs about 21p per wash before drying. Water at 0.35p per litre adds about 3p. A tablet and rinse aid estimate of 18p brings the total to about 42p per wash. Across five cycles per week, the annual cost is a little over £100 before standing charges.
If the same household chooses heated drying that adds 0.35 kWh per cycle, each wash costs about 9p more at the same electricity rate. Over five cycles per week, that is more than £22 per year. The saving is not huge, but it is easy to capture when air drying is practical.
FAQ
Is an eco programme always cheaper?
Often, but check the manual. Eco programmes usually reduce energy by using lower temperatures and longer time, but appliance design and soil level still matter.
Should I pre-rinse dishes?
Scrape plates, but avoid hot-tap rinsing unless the manual or hygiene situation calls for it. Hot water used before the dishwasher can move the cost away from the machine and onto the boiler.
Can I use this for a slimline dishwasher?
Yes. Enter the slimline model’s kWh, litres and cycles. Do not assume slimline always costs less; smaller capacity can mean more cycles.
Why is detergent included?
Tablets, powder, salt and rinse aid can cost as much as the electricity for a low-energy wash. Including them gives a more realistic per-cycle figure.
Should I include the standing charge?
Usually no for an appliance-only estimate. Include it only when you are costing a separate electricity supply or a whole-property bill.
Sources
- Ofgem (2026) ‘Energy price cap unit rates and standing charges‘. Office of Gas and Electricity Markets.
- Energy Saving Trust (2026) ‘Home appliances and energy use‘. Energy Saving Trust.
- European Commission (2025) ‘Dishwashers: ecodesign and energy labelling‘. European Commission.