The overall Which? test score is made up of the following star ratings, all determined by our rigorous lab tests.
How we test cleaning
To test how well each dishwasher cleans, we dirty a range of dishes, glasses, cups and cutlery. Our menu of challenging grub and grime includes milk, tea, minced meat, eggs, oat flakes, spinach and margarine.
How we test drying plates & cutlery
We inspect each item in the load after the wash has finished and score each and every item for cleanliness and dryness.
How we test drying plastic
We throw in a plastic tub as it is an extra challenge to get completely dry. These are harder to dry as they don't retain heat like crockery or glass does.
How we test not leaving watermarks
The very best dishwashers will also prevent watermarks from developing on your cutlery, plates and glasses by whisking away any droplets before they can turn into watermarks. We check for this on every item.
How we test energy efficiency of main program
We don't rely on the energy label to tell us how efficient a dishwasher will be. We run our own energy tests, measuring how many kWh the dishwasher uses for each program we test.
How we test energy efficiency of eco program
We measure how many kWh the eco program uses on an empty load and compare this others to see how efficient the dishwasher is.
How we test water efficiency of main program
We measure the flow of water in and out of the dishwasher to calculate the amount of water used in the main program.
How we test water efficiency of eco program
We measure the flow of water in and out of the dishwasher to calculate the amount of water used in the eco program.
How we test ease of use
Ease of use is based on an expert panel assessment of how easy it is to load the dishwasher, adjust the height of the upper rack, and use the controls and door panel.
How we test quietness
We assess how noisy the filling and washing stages of each dishwasher are, listening out for any loud or particularly irritating noises or tones. A five-star quietness rating will be almost silent, while a one-star will be very noticeable.
