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

New study by Which? crunched the numbers to find the cheapest UK supermarket, with Lidl coming out top.

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

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 August the team at Which? monitored the price each day of 23 items to make up its basic trolley. These include own-brand products like apples, eggs and tomatoes as well as branded items like Kenco coffee, Oxo stock cubes, and Twinings English breakfast tea.

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.

Own-label melon had some of the biggest price differences, costing £1.31 less at Lidl than at Waitrose, while there was also a difference of £1.25 on the price of PG Tips tea bags depending on your supermarket of choice.

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? carries out a similar study with a total of 82 items. That’s the original 23 goods and an additional 59 items on top.

This larger shopping list includes more branded items, like Branston baked beans and Colgate toothpaste. 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.

First is just how good value Asda is compared to the other supermarket mainstays ‒ it’s £9 a week cheaper than even its nearest rival, the sort of saving that over the long term is really noticeable.

Which? pointed out that Asda has now been the cheapest mainstream supermarket for 20 straight months.

The fact that Tesco is also the same price as Ocado is also notable, given the reputation that Ocado and Waitrose have of being something of a premium brand.

Where do we want to shop?

The bigger supermarkets have done pretty well over the last year and a half, in part due to the fact that they offered delivery or click and collect services.

In the middle of a pandemic, with many people uneasy about shopping in-store, that was a compelling proposition.

But there are signs that as the pandemic eases, we are starting to shop around a little more.

Data from the Kantar WorldPanel, which looks at the market share of supermarkets in the UK, shows that since the start of the year Tesco (-0.1%), Sainsbury’s (-0.7%) and Asda (-0.1%) have all seen their market share fall.

By contrast, Aldi (0.8%) and Coop (0.6%) have seen market share gains, while Lidl’s is unmoved.