Cheapest supermarket of the year revealed

Aldi has officially been crowned the cheapest supermarket of 2025. 

Each month, we analyse thousands of grocery prices to work out which major supermarket has the lowest prices.

Aldi was cheapest for 10 months in 2025, with Lidl cheaper for just two months - in July and October. 

Read on to find out how much you could save by switching supermarkets.

Aldi is the cheapest supermarket of the year

Aldi has now been cheapest supermarket of the year five times in a row. Lidl won the title in 2020, but Aldi has won every year since then.

However, Lidl is starting to close the gap. It went 20 months - from November 2023 to June 2025 - without winning the monthly contest, but has won it twice since then.

Our analysis shows you can save significant sums of money if you switch supermarkets - with the most expensive supermarket costing on average 35% more than the cheapest across 2025.

• Find out more: How to spend less at the supermarket

Cheapest supermarket in December

We checked the prices of 68 popular branded and own-brand groceries, including milk, cheese and Hovis sliced bread, at eight of the UK's biggest supermarkets throughout December to see how they compared.

The table shows how much our shopping cost on average:

Aldi was the cheapest for our shop - but only just; it beat Lidl by 10p.

The next cheapest was Asda, which doesn't offer loyalty prices in the same way as the others. It was 9% more expensive than Aldi for our shopping list.

Meanwhile, shopping at Tesco without a loyalty card was cheaper than shopping at Morrisons or Sainsbury's with one.

Tesco had Clubcard prices on 16 items on our list, while Sainsbury's was running Nectar price promotions on 12 items. Meanwhile, Lidl had one item on our list with a loyalty discount, but only for a couple of days, so it didn't affect the overall monthly average. Morrisons also had one item on a loyalty discount.

Waitrose does offer some loyalty prices to members, but there were none for items on our shopping list this month. 

Waitrose was the priciest supermarket again this month, averaging £170.46 – that's £46.86 (or 38%) more than Aldi.

• Find out more: cheapest supermarkets of 2025

What about a bigger shopping list? 

When we looked at a much larger selection (180 items), including more branded groceries, there were bigger savings with the loyalty schemes. 

Asda came out cheapest for the 12th month in a row, beating Tesco with a Clubcard by £78.35.

Tesco with a Clubcard – which had loyalty prices on 79 of the items – was the second cheapest, followed by Morrisons with More.

Waitrose was most expensive again, at £529.17 – 17% more than Asda. 

We couldn't include Aldi or Lidl here as they didn't stock all the branded items on our list.

You'll pay a lot more if you stock up at Sainsbury's or Tesco without a loyalty card, but only slightly more at Morrisons.

For shoppers without a Nectar card, Sainsbury's was the second most expensive after Waitrose. 

This longer list included 79 items on loyalty discount at Tesco, 70 at Sainsbury's and just two at Morrisons. 

• Interested in more than just price? Shoppers have rated product quality, customer service, online deliveries and more to reveal the best and worst supermarkets.

How much of a discount do loyalty cards give?

Based on our smaller list of products, having a loyalty card would save an average of 0.01% at Lidl, 0.12% at Morrisons, 1.6% at Sainsbury's and 2.36% at Tesco over the month.

For our longer list, which included more branded groceries and a wider selection of items with loyalty discounts, the savings were generally much more substantial – 6.39% at Tesco and 6.63% at Sainsbury's. However, savings were still only 0.3% at Morrisons. 

The discounts offered by loyalty cards may sound good, but that's only if you can access them. Our research has found that millions of people can't access loyalty promotions because they're not eligible to join supermarket member schemes due to their age, lack of address or difficulties with digital access. 

We think some supermarkets could do more to ensure certain groups of shoppers, such as those without a smartphone or under-18s, can access – or know how they can access – loyalty prices.

• Find out more: loyalty schemes compared

What's happening to grocery prices?

Annual inflation for supermarket food and drink has eased slightly to 4.3% (down from 4.7% in November), according to figures from Worldpanel by Numerator.

Prices are rising fastest for chocolate, coffee and milk/cream. They're falling fastest for paper products such as loo rolls and kitchen paper, sweets and household cleaning products. 

Last month, we revealed that some popular Christmas food and drink had soared in price, with some festive chocolates rising by more than 70%.

Our food inflation tracker shows that chocolate has seen particularly high annual inflation – 14.2% in November 2025, which was the highest across all the food and drink categories we looked at. 

Among the sweet treats that saw significant price hikes were:

• Lindt Lindor Milk Chocolate Truffles Treat Box (37g) at Asda, which jumped 72% - from £1.15 to £1.98
• Cadbury Dairy Milk Chocolate Puds Multipack 175g (5 x 35g), up 67% at Morrisons, from £3 to £5
• Terry's Chocolate Orange Dark Ball (145g) went up 67% at Tesco, from £1.50 to £2.50.

Global cocoa prices rose sharply early last year, following poor harvests in West Africa. However, commodity prices are now falling, with better harvests expected this year. 

• Find out more: check what's happening to prices by supermarket, category of food and ranges using the Which? food and drink inflation tracker

How Which? finds the cheapest supermarket

We check the prices of hundreds of grocery items at eight major supermarkets, using an independent price-comparison website. 

For each supermarket, we calculate the average price of each item across the month, then add those up to get each supermarket's average total price. 

For the annual cheapest supermarket award, we look at which supermarket has been cheaper for more months.

What items are on the list?

Our shopping list comprises the country’s most popular and widely available groceries, based on extensive market analysis. 

It includes branded items such as Cathedral City cheddar and Hellmann's mayonnaise, as well as own-brand products like potatoes and baked beans. 

Own-brand items won’t be identical across supermarkets, but we’ve ensured everything we’ve compared is as similar as possible, based on several factors, including quality and weight.

Which? never shares the full list of products used in its analysis, as we want to avoid any attempts by supermarkets to skew the results. 

We don't want supermarkets to compete with one another to lower prices only on the items they know they'll be judged on. Instead, we want retailers to work to make groceries affordable across the depth and breadth of their available lines.

What about special offers and loyalty prices?

We include special offers but not multibuy discounts. 

We are only able to include loyalty prices that apply to all members of a scheme (where there's one price on the shelf for shoppers with a loyalty card and another for those without). Currently, this type of two-tier pricing is used at Lidl, Morrisons, Sainsbury's, Tesco and Waitrose. 

We're unable to include discounts that are personalised to selected members, and we can’t factor in points or other rewards, as these vary between customers and don't always have a quantifiable monetary value.

• Find out more: how to spend less at the supermarket

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