Fridges: How we test fridges

Fresh food inside of a fridge

Which? tests reveal the best fridges

A great fridge will chill your groceries quickly to keep them fresher for longer, and keep food at a consistent temperature when your kitchen heats up or cools down. It will run quietly, offer plenty of useable storage space, and won't add a fortune to your energy bills.

To find the models that fit this bill, we carry out more than 200 checks, measurements and tests on each fridge at our temperature-controlled labs.

Head to our fridge reviews to find out:

  • How well will the fridge chill my food?
  • Will the fridge keep my food safely chilled?
  • Is the fridge energy efficient for the amount of food it can store?
  • Can you trust the fridge thermostat?
  • Should I buy it?

If you're not already a Which? member, you can try Which? for £1 to find out which are the best fridges and get full access to all the reviews on our website.

Video: What makes a Best Buy fridge?

Only the very best products can be Which? Best Buys. Our video shows you what you can expect from a Best Buy fridge, which includes quick and safe chilling so your food will last longer, and energy efficiency for its size - so it doesn't add any more money than it should to your energy bills.


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How well will the fridge chill my food?

The faster your groceries chill to below 5°C, the longer they’ll last and the more nutrients they will retain. To challenge fridges, we set the room temperature to 25°C and part-fill the compartments with gel packs to simulate food already stored inside.

We use gel packs and temperature probes to test cooling speed

We then add a light load of gel packs to the fridge – roughly equivalent in size to what you'd buy when you do a top-up shop for fresh food – and record the time taken for the packs to reach 5°C.

Will the fridge keep my food safely chilled?

We test fridges to check they will keep your food safely chilled 24/7. But room temperatures can vary widely over the course of a day and at different times of the year. So we raise the temperature in our test chamber to 32°C and see whether the gel packs inside remain at the required 0-5°C. We then lower the room temperature to a chilly 10°C and re-check the temperature of the gel packs.

We also record the temperature of gel packs on the top, middle and bottom shelves and check how much the temperature varies. If your fridge doesn’t cool evenly across all of the shelves it could have warm pockets or icy patches, which could cause your food to spoil.

Is the fridge energy efficient for the amount of food it can store?

Running a fridge can be pricey – because it’s always switched on you will constantly pay to power it. We measure how much energy each fridge uses to keep cool over 24 hours, as well as how much it uses to chill fresh food. We then calculate what this will add to your energy bill. 

Check out the specification tab for each fridge review to see how much it costs to run each year.

And to see whether a fridge is cheap to run for its size, we also rate its energy use against the amount of useable storage space it offers.

The more storage space inside your fridge, the more groceries you can pack away and the less frequently you’ll need to shop. But two appliances with the same external size might have more than 20% difference in useable space due to differences in design.

Manufacturers’ claimed capacities are usually measured with all of the shelves, drawers and door racks taken out, which makes you think you have more storage space than you actually do. We measure storage space with all of the storage features in place and don’t count any wasted areas. Our sizes give a more realistic indication of the amount of space you can actually use for storing groceries.

Can you trust the fridge thermostat?

thermostat 2

We test whether the thermostat will accurately set your fridge running at 0-5°C 

Keeping your food chilled between 0-5°C is crucial, as these temperatures will keep your food fresher for longer and help prevent harmful bacteria from growing.

When you’re setting up your fridge in your kitchen for the first time, most instruction manuals will recommend a thermostat setting. We test how accurate these are by following the instructions and recording the temperature of gel packs in the fridge.

The best appliances will chill to perfect temperatures as soon as you’ve set them up. But the worst are way off, leaving food too warm, which might make your food go off more quickly than it should – so you’d need to use a fridge thermometer to get the running temperature right.

How easy is it to use and clean the fridge?

Some fridges are easier to set up and use than others. We rate the type of display, position of the thermostat control and how easy it is to adjust, and whether it comes with a quick chill or door-open alarm.

We also rate how sturdy the shelves, drawers and/or compartments are, the quality of the storage features and how easy the appliance is to clean. In total, we carry out 40 ease-of-use checks and tests on each fridge; a fridge might be brilliant at its job, but if it's difficult to use or clean, then it might not be the one for you.

Should I buy it?

All of these tests contribute to a fridge's overall Which? test score. However, some tests mean more than others, so here is how each test contributes to the final score. The overall score ignores price and is based on:

78%The score a fridge needs to earn to be a Which? Best Buy

  • 30% Cooling speed
  • 20% Energy use  
  • 15% Temperature stability during everyday use
  • 10% Temperature stability in changing room temperatures  
  • 10% Accuracy of recommended thermostat setting  
  • 10% Ease of use and cleaning  
  • 5% Noise  

A fridge needs to score 78% or above in our tough tests to qualify as a Best Buy. Fridges that score 45% or less are highlighted as Don't Buy models to avoid.

Our reviews also reveal our expert verdict on whether we think each fridge is a good buy for its price.

Which? refrigeration testing

We constantly improve our fridge tests to ensure only the very best models are Best Buys. This means that newer models have been tested and scored in a slightly different way compared with older models; scroll down to read more about this.

The section below outlines the testing and score changes made in the past five years. You can see when each fridge was tested under the ‘Full specification’ tab in each review. While the test scores for all the fridges on our website don't directly correspond, you can still compare them generally, and each score gives a very good indication of the overall performance of each fridge. Plus you can read our expert verdicts to find out more about any fridge you're interested in buying.

Fridges tested before 2012

To see how quickly fridges could chill the contents of a weekly shop, we used a larger load of gel packs in our cooling-speed tests. We also used an ambient room temperature of 20°C for the cooling-speed and energy-use tests.
The score is based on: temperature stability and evenness (50%), cooling speed (10%), accuracy of thermostat (10%), energy use (10%), ease of use and cleaning (10%) and noise and vibration (10%).

Fridges tested 2012 – 2014

A survey of Which? members (August 2011) revealed that more than 90% add fresh groceries to their fridge several times a week, and most keep it nearly full most of the time. We changed our cooling-speed test to match this habit more closely by adding a lighter load of gel packs and by making sure the fridge is already nearly full, relative to its size.

We also raised the typical ‘room’ temperature in our test chamber from 20°C to 25°C to see how well each appliance keeps cool when it’s forced to use more energy – just as it is in your kitchen when you're cooking and when the fridge door is opened and closed repeatedly.

The score is based on: temperature stability and evenness (45%), energy use (15%), cooling speed (10%), accuracy of thermostat (10%), ease of use and cleaning (10%) and noise and vibration (10%).

Latest fridges tests - from 2014

To find the best fridges for keeping your groceries fresher for longer, we’ve raised the amount that cooling speed contributes to the final score to 30%.

In light of rising energy costs, we now take into account the amount of power a fridge uses to chill fresh food – to give you a more accurate idea of how each model might impact on your energy bills and which are more energy efficient than others. We’ve also increased the amount that energy use contributes to 20% of the final score.

Because our energy calculations are now more accurate, running costs for models tested before and after 2014 shouldn’t be directly compared. However, running costs don't contribute to the total test score, so this change doesn't influence performance ratings.

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