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

A significant portion of the money we spend each month goes to our chosen supermarkets.

This has only become more significant in recent months, with food price inflation now at the highest level seen since the late 1970s.

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

So which supermarket is the cheapest?

Are you better off heading to one of the deep discounters which are becoming more popular within the UK?

The latest supermarket study from consumer champion Which? certainly suggests so.

How are supermarkets judged?

Throughout December the team at Which? monitored the price each day of 48 items to make up its basic trolley.

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

It then uses 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, they cost as much as £30 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 149 items.

That’s the original 48 goods and an additional 101 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:
 

Once again Asda came out top. It has been the cheapest supermarket for the bigger trolley since January 2020, and works out a little more than £50 cheaper than Waitrose for the same trolley of goods.

Getting better value

Which? aren't the only ones who study the prices charged by our big supermarkets.

There’s also a regular investigation held by Alertr, which tracks the prices of 42 items included in the basket of goods used by the Office for National Statistics to monitor inflation.

These include the likes of eggs, milk, bread, pasta and rice.

It found that Asda was the cheapest, with a typical basket costing £123 during December. Here’s how the various supermarkets shape up, including the change from the month before.
 

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 that the market share of some of the biggest names has dropped over the last year.

Tesco for example has dropped from 27.9% to 27.5%, Sainsbury’s has fallen from 15.7% to 15.5%, Asda has moved from 14.2% to 14%, and Morrisons has declined from 10.1% to 9.1%.

By contrast, the market share of Aldi has moved from 7.7% to 9.1% over the same period, while Lidl’s has grown to 7.2% from 6.3%.  

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.