Aldi pips Lidl to cheapest supermarket of the year – as Which? research shows grocery prices rising sharply

Aldi has narrowly pipped rival Lidl to be named cheapest supermarket of the year by Which? – as the consumer champion finds grocery costs going up even at budget stores.

Which? tracked hundreds of thousands of grocery prices across the UK’s eight major supermarkets throughout 2021 to find out how much each shop was charging for everyday items such as bread, milk and eggs. 

While revealing which supermarket was the cheapest over the course of the year, Which?’s analysis also shows that prices have been creeping up, with supermarkets charging up to nine per cent more in December than they did last January.

Overall Aldi was the cheapest supermarket for six of the 12 months while Lidl was the cheapest for five including December 2021. For one month, January 2021, Aldi and Lidl were tied with a basket of 19 items coming in at £18.45 at both discounters. 

Lidl, winner of the cheapest supermarket accolade for 2020, was the cheapest supermarket in December, at £23.29 for a basket of 22 groceries, just beating Aldi, where the basket was £23.64. Meanwhile, Waitrose was more than £9 pricier than Lidl, at £32.85 – that’s 41 per cent more. In fact, Waitrose was consistently the most expensive across the 12 months. A basket of everyday items cost from £6 to over £10 more at Waitrose per month than the cheapest supermarket.

Alongside the price comparison of a basket of groceries at all eight supermarkets, Which? also compares a larger trolley packed with a greater selection of items such as Cathedral City cheddar and Kenco coffee, that are not always available at the discounters (Aldi and Lidl) – meaning they cannot be included in this bigger comparison.

Asda was the cheapest of the traditional supermarkets and has been for every month for the last two years now. Waitrose was also the most expensive each month except one in 2021 for this wider analysis.

The analysis also revealed that prices had risen significantly over the course of the last 12 months. Which? found that prices for the basket of everyday items had risen the most at Waitrose – by a massive nine per cent, compared to the average three per cent rise across all eight supermarkets.

Even prices at Aldi and Lidl rose between January and December 2021 – in both cases at more than the average rate. 

Sainsbury’s managed to keep its prices relatively steady over the year with the smallest price rise of 0.59 per cent in Which?’s analysis.

Which? also found that some own-brand grocery items rose more in price than others across all eight supermarkets. The biggest increases among items in Which?’s basket were for Royal Gala apples (up 14%), free-range eggs (up 12%), brown onions (up 11%), skimmed milk (up 10%) and semi-skimmed milk (up 9%).


Ele Clark, Which? Retail Editor, said:

“No one wants to overpay for basic groceries, especially when a cost of living crunch is putting extra pressure on household budgets.

“Our findings show that while prices are going up, some supermarkets are passing their rising costs onto shoppers more than others. As well as choosing a supermarket that is cheap overall, other ways to save include swapping from branded to own-brand products, sticking to a shopping list and resisting the temptation to pick up special offers you don’t need.”



Notes to editors: 

Which? Analysis

  • Which? checks the prices of hundreds of grocery items across eight major supermarkets every day throughout the year, using an independent price comparison website.
  • For its ‘cheapest supermarket of the month’ analysis, Which? Works out the average price for each item at each supermarket across the month, and add the averages up to get an average trolley price for each store.
  • Which? includes special offer prices but not multibuys, to keep it as fair as possible.
  • The shopping list combines branded items such as Kenco coffee, Oxo stock cubes and PG Tips tea bags with own-label products, including onions and milk. Of course, own-brand items aren’t exactly the same at different supermarkets, but Which? uses experts to ensure that the products are as comparable as possible based on a range of factors, including weight and quality.
  • As well as a selection of everyday own brand items for the comparison which includes the discounters, Which? also compares a trolley packed with many more items, the original basket as well a greater selection of branded items, such as Cathedral City cheddar and Colgate toothpaste, that are not always available in the discounter supermarkets – so for this bigger trolley Which? is not able to include Aldi or Lidl.
  • In December, Asda, at £135.07, was the cheapest of the traditional supermarkets for this larger trolley. It was £18.30 cheaper than the most expensive supermarket, Waitrose. 
  • While Waitrose was the most expensive almost every month for both the smaller basket and the larger trolley of items, Ocado was most expensive in January 2021 for the bigger trolley.

Price rises

Which?’s analysis uncovered an average price rise of 3.4 per cent for a trolley of 19 items across all the supermarkets. Waitrose prices went up the most (9.2%), and Sainbury’s the least (0.59%)

Supermarket Grocery basket price rise Jan – Dec 2021 (%)
Sainsbury’s 0.59%
Tesco 0.89%
Ocado 1.62%
Morrisons 2.50%
Asda 2.89%
Aldi 4.32%
Lidl  5.13%
Waitrose 9.20%

The products that rose the most across all of the supermarkets were: 

  • Own label royal gala apples: up 14%
  • Own label free-range eggs: up 12%
  • Own label brown onions: up 11%
  • Own label fresh skimmed milk: up 10%
  • Own label fresh semi-skimmed milk: up 9%

Other info

  • Market analyst firm Kantar has also found grocery price inflation reached 3.5 per cent in the four weeks to December 26, its highest level since spring 2020 (when promotions were cut to maintain availability). That’s an extra £15 on shoppers’ average monthly grocery bill. Before spring 2020 you would have to go back to January 2018 to see higher inflation. 
  • Kantar said prices were rising fastest for groceries such as fresh beef, savoury snacks and skincare. But the good news is they are falling for fresh bacon, bath and shower products and spirits.
  • Meanwhile several big food and drink companies have warned they are preparing to increase prices, including P&G, Kraft Heinz, Mondelez, General Mills and Colgate-Palmolive. Inflation is being driven by supply chain pressures, rising wages and freight costs. 

Useful links – 

  • How to spend less at the supermarket – 
  • Cheapest supermarket by month – – Which?

About Which?

Which? is the UK’s consumer champion, here to make life simpler, fairer and safer for everyone. Our research gets to the heart of consumer issues, our advice is impartial, and our rigorous product tests lead to expert recommendations. We’re the independent consumer voice that influences politicians and lawmakers, investigates, holds businesses to account and makes change happen. As an organisation we’re not for profit and all for making consumers more powerful.

The information in this press release is for editorial use by journalists and media outlets only. Any business seeking to reproduce information in this release should contact the Which? Endorsement Scheme team at

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