How we test freestanding cookers

No one tests and rates cookers as thoroughly as we do at Which?, so read on to find out more about our independent cooker reviews
Jonny MartinResearcher & writer
Electric cooker

Our independent tests reveal whether a cooker’s oven sticks to the temperature you set, and whether its grill and hob will brown and fry your food to perfection. 

Unlike free-to-access websites that typically get all the cookers they review free from manufacturers or their PR representatives, we buy all the appliances we test ourselves. That means you can have complete trust in our verdicts.

The Which? overall percentage score is calculated purely on the measurements and ratings supplied by our laboratory, meaning there's no room for unconscious bias when giving our ratings.

To see our top cooker recommendations and buying advice, see our guide to the best freestanding cookers. 

Video: how we test freestanding cookers

Watch this video to discover more about our extensive testing program and why our cooker tests are different.

What are Which? Best Buy, Great Value and Don’t Buy freestanding cookers?

The Best Buy, Great Value and Don't buy logos

A quick guide to the recommendations you'll see on our reviews.

Best Buy freestanding cookers

Best Buys are given to the freestanding cookers that impress most in our tests. A cooker that scores 67% or more is a Best Buy and comes with a firm overall recommendation, although you should still read our full reviews to check for any weaknesses that might impact your buying decision. 

Best Buy cookers typically tick the most important boxes - they heat up quickly and accurately, grill effectively and have decent built-in hobs. 

Great Value freestanding cookers

Freestanding cooker prices vary significantly, with some premium models costing more than £1,700.

Great Value cookers are at least 20% cheaper than the average cooker we test, and score 60% or more - so you can be sure you'll be getting a decent product at a decent price.

Look out for Great Value models that also score highly enough to be Best Buys.

Don’t Buy freestanding cookers 

Any cooker that scores 45% or lower is a Don't Buy that's best avoided.

These models tend to fall down in the most important areas - they're awkward to use, with ovens that can't reliably bake a cake and hobs you'd struggle to even heat baked beans on. 

How is the Which? score calculated?

The Which? overall score is a percentage. This score only takes into account the results of our tests and ignores price completely.

This means all the cookers are tested on exactly the same scale, so you can compare any cooker at any price and see how it measures up against its rivals in key areas, regardless of its fuel type.

Weightings and star ratings

A Which? overall score is made up of dozens of individual tests and checks, from key factors such as the hob's speed of heating up, and how well the heat from the grill is distributed across a sheet pan. 

To keep things simple, the most important scores are shown as star ratings out of five in the test results section of each review. This gives you an easy-to-compare list of the strengths and weaknesses of different models.

You've told us that the most important features of a freestanding cooker are the oven, grill and hob, so we put more emphasis on these areas of our tests when we award a cooker an overall score. 

On top of this, we know that how easy the cooker is to use and clean are both considerations, along with how efficient the cooker is.

The full score breakdown is as follows:

  • 40% oven performance
  • 25% ease of use and cleaning
  • 20% hob performance
  • 10% grill performance
  • 5% energy efficiency

Read on to find out exactly what goes into each of these scores.

Our key testing criteria 

Below are the key cooker testing categories and how we evaluate each one:

Oven performance

Key question: Does the oven heat up quickly and spread heat evenly?

Everyone varies the temperature at which they use their oven, so our tests check how quickly the oven in each cooker reaches two set temperatures. 

We set conventional electric ovens and gas ovens to heat up to 180°C  (gas mark 4) and 200°C (gas mark 6), and fan-assisted electric ovens to 150°C and 180°C. As well as noting the speed at which they reach these temperatures from cold, we then record how closely each oven sticks to the set temperature. Our tests have found ovens that veer wildly away from what you would expect – sometimes by more than 40°C. Top-scoring Best Buy ovens, however, stick closely to the expected temperature.

Shortbread baking

Next, we bake a tray of shortbread in the oven. This delicate bake clearly shows how effective the cooker is at spreading heat evenly throughout the oven cavity. Ovens that leave pale parts or burnt corners get marked down in our tests, while those that turn the shortbread an even golden brown across the whole tray get top marks. See the picture below to see the kind of results ovens produce in our lab tests.

Cake baking test

Our second baking test involves making a large sponge cake and measuring its vital statistics when it emerges from the oven. If it's well risen and evenly browned, it gets a high score, but flat, sunken or unevenly baked cakes lose points. Below is an example of a well-risen sponge baked in the oven of a Best Buy cooker.

Key question: How much can you fit into each cooker's oven?

Which? oven capacity test

Manufacturers give the total internal dimensions of an oven, but this doesn't give a clear picture of what you will actually be able to fit in. So we use a plastic turkey, chicken or roast beef joint and put it on roasting tray – then we add another tray if we can – to find out whether you'll be able to cook a full Christmas dinner in there, or if you'll be limited to a smaller Sunday roast. If the freestanding cooker has more than one oven, we try out both.

As well as using the fake roast joints, we also record the useable space within each oven. We measure from side to side, and the distance from the inside of the door to the back of the oven. When it comes to the height, we measure from the top of the lowest shelf to 3cm below the top of the oven, to give a real feel for the actual height available.

Oven performance accounts for 40% of a cooker's score.

Ease of use

Key question: Is the cooker easy to use?

An independent panel judges each freestanding cooker for ease of use. They look at how easy it is to use the settings on the ovens, grills and hob, as well as how clear the markings are and whether you have a clear view into the oven while food is cooking.

Key question: Is the cooker easy to clean?

To assess the ease of cleaning a cooker, we intentionally create common kitchen messes on various parts - including boil-overs on the hob and baked-on grime in the oven. Our expert assessors then begin cleaning with common household products, noting things like how difficult it is to access certain nooks and crannies and how easy it is to lift off stains and residues. 

We also look at the performance of inbuilt self-cleaning features, and whether parts are dishwasher proof.

Ease of use accounts for 25% of a cooker's score.

Hob performance

Key question: How effective is the cooker's hob? 

When you're in a hurry to heat your soup, a freestanding cooker with a speedy hob should do the job. We test how rapidly each hob will heat up a pan filled with water from 15°C to 90°C. Quick hobs take less than five minutes, but the slowest will keep you waiting more than double this time. Best Buy hobs also excel at the other end of the scale, allowing you to simmer delicate ingredients.

If you regularly fry bacon, then you'll be interested in our heat-distribution test, where we measure how well heat spreads across the base of a frying pan – the best hobs spread the heat evenly rather than concentrating it in particular spots. Our final tests involve recording what happens when you power down the hob – some retain heat and will keep cooking your food, while others cool down quickly.

Hob performance accounts for 20% of a cooker's score.

Grill performance

Key question: How evenly does the cooker's grill brown food?

Grill test

We cut the crusts off white bread and cover the cooker's grill pan with it, to let us see how far and how evenly the grill spreads its heat. A great grill can brown virtually all of the bread, but our tests have found many that struggle to heat more than 50% of the area – and the worst models only toast bread that is placed directly under the element. This means that you would find yourself shifting food around to get anything approaching even browning.

Grill performance makes up 10% of a cooker's score.

Energy efficiency

Key question: How energy efficient is the cooker?

As all food is variable, we maintain consistency by heating up 2kg of bricks in the main oven for 1hr 40 mins. This simulates about how long you'd roast a whole chicken for. In freestanding cookers the conventional electric ovens are set at 200°C, electric fan ovens to 170°C and gas ovens to gas mark 6.

We measure how much energy each oven uses, and convert this into a score based on the running costs for each model.

Energy efficiency makes up 5% of a cooker's score.

Find a great freestanding cooker with Which? reviews

Only a small fraction of freestanding cookers achieve the 'holy grail' of swift, consistent heating and are exceptional enough to be christened Which? Best Buy freestanding cookers. Price doesn't necessarily indicate quality – we've assessed some top-tier models that struggle to maintain a steady temperature, despite their eye-watering price tags.

We're here to guide you away from inefficient freestanding cookers that are energy hogs and leave your meals unevenly cooked or burnt. We help you identify the models that not only warm up your meals, but also your kitchen experiences, making each cooking session a pleasure, not a chore.

Browse all of our freestanding cooker reviews.