The overall Which? test score is made up of the following star ratings, all determined by our rigorous lab tests.
How we test energy efficiency
We simulate roasting a 2kg chicken and record how much energy each cooker uses across one hour and 40 minutes.
How we test hob performance
We test how powerful a hob is by recording how long it takes to heat up a big panful of water. But we also test its ability at the other end of the scale and see how gently it can simmer. Next, we measure how well the heating zone or burner spreads heat across the base of a pan which indicates how evenly it will fry. Finally, we see what happens when you turn off the hob - and whether your food keeps cooking even when the power's off.