We compared the prices of 47 popular grocery items every day throughout November and found their total average cost was £76.77 at Aldi - over £20 cheaper than the priciest supermarket.
Here, we reveal how the UK's eight biggest supermarkets compare for pricing, plus which 'big four' grocer was cheapest for a trolley of 134 items.
Cheapest supermarket for a basket of groceries
Our basket of 47 items included Albert Bartlett Rooster potatoes, own-brand chicken and milk.
The chart shows how the groceries cost on average at each major supermarket:
Find out more:
How do bigger shopping lists compare?
We also compared the cost of a larger trolley of 134 items (the original 47, plus 87 more).
This larger-scale comparison included more branded groceries, including Bird’s Eye frozen garden peas and McVitie's biscuits. As the discounters don’t always stock branded products, we haven’t included Aldi or Lidl in this comparison.
The graph shows how much our larger trolley costs on average at each supermarket:
Our trolley cost £328.15 at Asda, comfortably beating the next-cheapest supermarket Morrisons by £10.01.
Our analysis also found that Waitrose was £41.65 pricier than Asda on average, with our big shop costing £369.80 at the high-end supermarket.
Find out more:Loyalty pricing affecting the rankings
Which? believes this may be due to an increased emphasis on loyalty pricing – for example, Tesco Clubcard and Sainsbury’s Nectar members get lower prices on some items – which appears to have pushed average prices up for those who aren't members of the schemes.
We don’t include loyalty prices in our supermarket price comparison as these aren’t available to everyone.
Find out more:What's happening to supermarket prices overall?
Year-on-year price rises for food and drink dipped slightly to 11% in the three months to 31 October 2023, according to Which? research.
Our latest figures – which we release every month – show that Lidl has the highest level of inflation, with prices up 11.6% year on year in the month of October.
Lidl was followed by Sainsbury's at 11.4%. This is possibly due to it offering more discounts only to Nectar card holders, which appears to have pushed up average prices for non-members.
Our inflation data is based on supermarkets' standard prices and doesn't take into account multibuys or loyalty scheme discounts.
When it comes to types of food, biscuits are still the fastest-rising in price of all 20 categories in our research. Chocolate, crisps and yoghurts are also among the worst-hit categories.
Find out more:16% of people skipping meals to save on food bills
Worries about food prices haven't eased, despite the dip in inflation - Which? research has found that 83% of people are worried about food prices.
We asked whether people had taken any action to combat higher food prices. Half said they'd switched to cheaper alternatives, while 38% bought extra items when they were on promotion.
Shockingly, 16% of people said they'd skipped meals to reduce their food spend.
There was a large increase in reported levels of financial difficulty in November 2023, as 9.8% of people said they had missed or defaulted on a loan, credit card, housing or household bill payment in the past month. This is the highest level recorded in the past three and a half years.
Find out more:Which? calls on supermarkets to do better
Which? has found that, while some good practice exists, many of the major supermarkets have not done enough to support their customers during the cost of living crisis.
Supermarkets could be doing more by ensuring their smaller convenience stores stock budget-range healthy food, especially in areas where this is most needed.
Given the urgency of the cost of living crisis, Which? is calling on the government to act now and work with supermarkets to secure changes that could make a real difference to millions of people struggling to put food on the table.
Do you want to see your supermarket take action to support people through the cost of living crisis?How Which? compares supermarket prices
We look at the prices of hundreds of grocery items at eight major supermarkets every day throughout the month, using an independent price comparison website.
We calculate the average price of each item at each supermarket across the month, before adding those up to get stores' average prices for a basket and trolley of products.
To keep things fair, we include special offers but not multibuys or loyalty-scheme discounts in our analysis.
Our shopping list includes branded items such as Cathedral City extra mature cheddar and PG Tips teabags, as well as own-label products such as smoked bacon rashers and little gem lettuce.
As own-brand items aren't identical across supermarkets, we use experts to ensure everything we’ve compared is as similar as possible, based on several factors including quality and weight.
Find out more:source https://www.which.co.uk/news/article/aldi-named-cheapest-supermarket-in-november-aYTGv4x3Rcxv