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 a deep discounter.

The cost of our food remains a concern.

While food price inflation has dropped from its 19.2% peak, it was still 5% for the 12 months to February 2024, according to the Office for National Statistics.

That’s why finding the best value for money when heading out for your food shopping is so important.

So which UK supermarket is the cheapest?

The cheapest supermarket

The team at Which? run a useful study each month, which in March involved monitoring the price each day of 71 items to make up its basic trolley.

It then used these daily prices to produce an average cost for that trolley of goods for the month.

Of course, when it comes to own-label items, what’s on offer isn’t identical between the different stores.

So Which? adapts the calculations to take into account things like weight and quality.

How the supermarkets compare

Here’s how the various supermarkets included in the study shape up, based on this basket of items:

Indeed, Waitrose is £37 more expensive than Aldi.

Interestingly, while Lidl dominated this study last year ‒ topping the table on 11 out of 12 months ‒ it is its deep discounter rival Aldi which has been claiming the top spot in 2024.

It’s also important to bear in mind that this study takes into account special offers, but not loyalty scheme discounts.

Given the way a host of supermarkets now offer lower prices on certain items to members of their loyalty schemes, it may be that the likes of Tesco and Sainsbury’s work out more budget-friendly if you are a Clubcard or Nectar member, for example.

The bigger trolley

Of course, most of us end up picking up a more substantial number of goods when we go grocery shopping, so Which? carried out a similar study with a total of 188 items.

That’s the original 71 goods and an additional 113 items on top.

Importantly Which? says that it doesn’t want to publish the list of items it uses for the study, 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:

In fact, July 2023 is the only time in which it hasn’t been the cheapest dating back to January 2020.

In this latest study, it was almost £50 cheaper than Waitrose, a difference that can really add up over time.

The Grocer study

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

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

Its latest survey had Asda come out top with the basket of selected goods coming to £82.39.

That was ahead of Morrisons (£84.14), Tesco (£84.52), Waitrose (£88.92), and Sainsbury's (£90.52).

Interestingly Asda would have been undercut by both Sainsbury’s and Tesco if you had access to the lower prices on offer to loyalty scheme members. 

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

Where do we want to shop?

Interestingly, our shopping habits ‒ and particularly the supermarkets we use ‒ are changing.

And 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 members. 

Tesco, for example, has grown its market share from 26.9% to 27.3% over the last 12 months, while Sainsbury’s has risen from 14.8% to 15.2% and Lidl is up from 7.4% to 7.8%.

Asda and Morrisons have probably been the biggest victims. Asda has crashed from 14.3% to 13.8%, while Morrisons has slid from 8.8% to 8.7%.

Aldi has also seen its share slip from 9.9% to 9.8%, while Co-op is down from 5.7% to 5.5% over the same period. Waitrose, meanwhile, is unchanged with a 4.5% share.

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