Aldi, Lidl, Tesco, Sainsbury’s, Asda: which is the cheapest UK supermarket?

If you are looking for the cheapest supermarket to do your weekly shop, new research suggests you'll be better off at Aldi.

Saving on the weekly grocery shop is a top priority for many of us trying to stay within budget as the cost of living remains high.

Food inflation increased to 2.3% in September, up from 2% in August and higher than its three-month average rate of 2.2%, says the British Retail Consortium. 

However, it currently remains at the lowest rate seen since November 2021.

But which UK supermarket is the cheapest?

The cheapest supermarket

The team at Which? run a useful study each month, comparing the average cost of doing the weekly shop at eight different UK supermarkets.

In September they checked the daily price of 59 groceries to form a basic trolley, and then used these to produce an average cost of the items during the month.

Of course, it’s worth bearing in mind that when it comes to own-label items, what’s on offer isn’t necessarily like-for-like between the different stores.

Here is a round-up of how the eight supermarkets performed:

As you can see from the table above, there’s a quite a difference between cost of a trolley of food sourced from the deep discounters and the more premium outlets such as Waitrose and Ocado.

Indeed, a Waitrose shop is almost £28 more expensive than Aldi.

Interestingly, while Lidl dominated this study last year ‒ heading the table in 11 out of 12 months ‒ Aldi has been claiming the top spot in 2024.

The analysis also shows that using a loyalty scheme, such as Tesco’s Clubcard or Sainsbury’s Nectar card, can also be a useful tool in trimming your shopping bill.

There is a £5 difference, for example, in the table above in shopping at Sainbury’s with or without a Nectar card.

The bigger trolley

Of course, many households pick up a wider range of items when they do their grocery shop, so Which? carried out a similar study with a total of 164 items in September.

That’s the original 59 goods and an additional 105 items.

Importantly, the consumer champion doesn’t disclose the list of products it includes in the research, to ensure supermarkets cannot ‘game’ the study by focusing price cuts on them.

However, as the additional items are not always available at the deep discounters, Aldi and Lidl aren’t included in this study.

Here’s how the supermarkets compare on the larger shopping basket:

The impact of loyalty schemes

Asda claimed the top spot for the bigger trolley, with Tesco (with Clubcard) coming a close second.

However, the supermarket came third from bottom for those shopping without use of its loyalty scheme (and even priced more expensive than premium brand Ocado).

Likewise, Sainsbury’s took third place for shoppers using a Nectar card but proved pricier than Waitrose for those shopping without it.

The Grocer study

Which? isn’t the only organisation to keep a keen eye on supermarket pricing.

Industry bible The Grocer also tracks prices, as well as other supermarket features such as service and product availability, with a rotating list of supermarkets each week.

Its latest survey for September had Tesco come out on top, with its basket of selected goods coming to £57.31.

That was ahead of Sainsbury’s at £57.92, Asda at £60.17, Morrison’s at £65.69, Iceland with £66.69 and Waitrose at £78.73.

Note, all the prices above include loyalty schemes.

A number of supermarkets had seen their average baskets fall in price compared to the same time last year, with Sainsbury’s down 7.3%, Tesco’s down 6.4% and Iceland’s falling 4.7%.

It’s important to note that the deep discounters were not included in this latest test ‒ when they were, they tended to perform particularly well.

Where do we want to shop?

With the cost-of-living crisis, it’s hardly a surprise that our shopping habits ‒ and particularly the supermarkets we use ‒ are changing.

However, it’s not in the way you might expect.

In previous years the likes of Tesco and Sainsbury’s have lost market share as shoppers have looked for cheaper deals, but they are recovering now, partly due to those lower prices for their discount scheme members.

According to research from Kantar, Tesco, has grown its market share from 27.4% to 27.8% over the past 12 months, while Sainsbury’s has risen from 14.8% to 15.2%, and Lidl’s is up from 7.6% to 8%.

Meanwhile, Asda’s has fallen from 13.7% to 12.6%, while Morrisons’ has slid from 8.6% to 8.5%.

Aldi’s market share has stayed static at 9.9% during the period, while Lidl’s has increased to 8% from 7.6% and the Co-Op’s has dipped to 5.9% from 6.1%.

Waitrose, meanwhile, is unchanged with a 4.6% share of the market.

The sales tactics employed by the big names are having an impact and suggest that shoppers are not entirely loyal to the deep discount chains.