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

The cost of our food has never been a bigger concern.

Figures from the Office for National Statistics (ONS) show that food price inflation is almost 15%, and while that is down on the last few months, it’s still putting our household finances under severe pressure. 

As a result, finding the best value for money when heading out for your food shopping has rarely been more important.

So which UK supermarket is the cheapest?

The cheapest supermarket 2023

The team at Which? run a useful study each month, which in June involved monitoring the price each day of 37 items to make up its basic trolley.

These include items like Heinz baked beans, milk and tea bags.

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:

As you can see, there’s quite a contrast there between the deep discounters and the more premium outlets like Ocado and Waitrose.

Indeed, they cost almost £15 more than the cheapest outlets.

This isn’t a new situation either.

Across 2022 as a whole, either Aldi or Lidl was found to be the cheapest supermarket in this study each and every month.

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 133 items.

That’s the original 37 goods and an additional 96 items on top.

This larger shopping list includes more branded items, like Cathedral City cheddar and Andrex loo roll.

And as they aren’t 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:

Asda regained top spot, having lost it last month to Morrisons. That was the first time since 2020 that another supermarket had beaten it in the study.

It worked out a whopping £43 cheaper than Waitrose.

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 £65.48.

That was ahead of Tesco (£68.31), Sainsbury’s (£68.82), Morrisons (£71.57) and Waitrose (£76.54).

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?

It’s clear that shoppers are increasingly switching to more budget-friendly stores as household finances come under ever greater pressure.

Data from Kantar WorldPanel shows how the market share of different supermarkets is changing, with the bigger names in particular losing shoppers.

Since the end of 2022 Tesco has dropped from 27.5% to 27%, Sainsbury’s has fallen from 15.5% to 14.8%, and Morrisons has declined from 9.1% to 8.7%.

By contrast, the market share of Aldi has moved from 9.1% to 10.2% over the same period, while Lidl’s has grown to 7.7% from 7.2%.  

The message seems pretty clear ‒ shoppers are more than happy to give the challenger names a go in a bid to get better value for money, a drive that's only likely to continue as the cost of living crisis continues.