Aldi has been crowned Britain's cheapest supermarket of 2025 with customers saving hundreds of pounds compared to its rivals over a year, a study found today.

The German-owned discounter which is now Britain's fourth biggest grocery chain was the cheapest in ten out of the 12 months, according to consumer group Which?.

This saw Aldi earn the organisation's cheapest supermarket title for the fifth year in a row - but Lidl was close behind with an average difference of just 77p each month.

Among the larger supermarket chains, Asda beat Tesco, Morrisons and Sainsbury's on price - even for those who are members of those retailers' loyalty schemes.

Waitrose was the most expensive supermarket, costing an average 35 per cent more than the cheapest for a smaller shop and 15 per cent more for a larger shop.

Experts track daily data for Aldi, Asda, Lidl, Morrisons, Ocado, Sainsbury's, Tesco and Waitrose to see prices for everyday items such as milk, bread and frozen peas

At the start of each month, Which? then reveals the cheapest supermarket of the previous month based on a price comparison of products matched across the eight chains. The study includes special offers and loyalty prices, but excludes multibuys.

In December, Aldi – which does not have a loyalty price scheme - was the cheapest for a list of 68 items, with the basket costing £123.60 on average across the month.

Aldi's main rival Lidl was a close second last month, costing just 10p more in December at £123.70, for both Lidl Plus members and non-members.

Lidl was the cheapest supermarket twice last year in July and October, and across the whole year the average monthly price difference between the two was just 77p.

At Asda, the same 68 items cost £134.89 on average last month - and, while still cheaper than most other supermarkets, it was still around £11 more than Aldi.

For the same items, the research showed Tesco Clubcard members would have paid £135.84 on average last month, compared with £139.12 without a Clubcard.

Meanwhile, the analysis showed Sainsbury's Nectar card holders would have paid £141.45, rising to £143.74 for those not on the loyalty scheme.

At the other end of the scale, Which? found the same basket cost £170.46 at Waitrose in December – £46.86 more than Aldi.

Over the course of the year, Waitrose was 35 per cent more on average than the cheapest supermarket and 38 per cent more in December.

Which? also compared the cost of a much larger weekly shop of 180 items among the six non-discounter supermarkets.

Aldi and Lidl are excluded from this comparison because of their smaller product range.

In December, Asda was the cheapest non-discounter supermarket with Which?'s list of items costing £450.82, continuing a pattern seen throughout the year.

Asda consistently beat Tesco, Sainsbury's and Morrisons, even when loyalty prices such as Clubcard and Nectar were included.

Which? found Tesco Clubcard holders would have paid £462 on average in December for the same list of items – more than £11 more.

The analysis also showed Tesco shoppers without a Clubcard would have paid £493.53, or just under £43 more than those who shopped at Asda.

Shoppers at Morrisons would have paid £466.04 with a loyalty discount or £467.46 without - around £15 or £17 more than at Asda.

At Sainsbury's, Nectar holders would have paid £468.61, while non-members would have paid £501.89 – more than £51 more than an Asda shopper.

Ocado shoppers would have paid £498.19 in December for Which?'s list of 180 items - over £47 more than at Asda.

Once again, Waitrose was the most expensive supermarket for the larger shop at £529.17.

In December, the same trolley cost £78 more than at the cheapest supermarket - a difference of 17 per cent.

Which? retail editor Reena Sewraz said: 'Aldi's consistent performance shows why it has been crowned the UK's cheapest supermarket for the fifth year in a row.

'While Lidl continues to provide strong competition among the discounters and is still a great option for those looking to save on their shopping, Aldi was cheapest in most months and offered the lowest prices overall.

'Our analysis also shows that Asda remains a strong choice for shoppers looking for a bigger range of branded goods at lower prices.

'With food bills still a major concern for many households, it really does pay to shop around – choosing one supermarket over another could save shoppers hundreds of pounds over the course of a year.'

The two lists of groceries are made up of some of the UK's most popular groceries, based on industry data on sales value and availability.

Because the main list of around 200 groceries remains unchanged each month, Which? does not share this with retailers because it wants to avoid any attempt to skew the results.

The Daily Mail has contacted all the named supermarkets for comment. 

Aldi said it was celebrating the title by releasing a collection of 'Brag Bags' which take a swipe at its rivals, with slogans such as 'These are not just regular prices; these are Aldi prices'; 'Aldi. No loyalty card needed' and 'Champagne taste, Aldi budget'.

Julie Ashfield, chief commercial officer at Aldi UK, said: 'Being named the UK's cheapest supermarket for the fifth-year running is something we're incredibly proud of.

'These fun limited-edition tote bags celebrate what Aldi does best - offering outstanding quality products at the lowest possible prices.'

An Asda spokesman said: 'We're pleased to see Which? once again recognise Asda as the lowest‑priced supermarket for the big family shop. 

'Our customers can be confident they're getting the best value on their favourite brands and the everyday products they buy the most, without the need for a loyalty card. Asda Price means clear, consistent pricing, that's available to everyone.' 

And a Waitrose spokesperson said: 'Great value is about more than just price, and we take pride in offering exceptional products with award-winning customer service.

'On top of this, our customers know that our products are sourced with care; our market-leading animal welfare standards include 100 per cent of our chicken meeting Better Chicken Commitment standards or higher, and a commitment to 100 per cent free range pork by 2027.'

Earlier this week, Aldi revealed a £1.65billion sales haul over the Christmas month as price remained the 'biggest priority' for shoppers.

The group reported a 3 per cent rise in total sales over the four weeks to Christmas Eve as it notched up a record 57 million transactions.

Aldi said sales jumped by more than 5 per cent in the final trading week leading up to Christmas, with around £500million rung up through its tills.

The performance for the month-long run-up marks a slight slowdown on the previous Christmas, when sales lifted 3.4 per cent.

Last week, Lidl cheered a 'record-breaking' Christmas as it revealed a 10 per cent surge in sales after nearly 51million customers shopped with the discounter in the festive run-up.

The group said its UK business made more than £1.1billion in turnover in the four weeks leading up to Christmas Eve.

Shopper numbers rose 8 per cent year-on-year to a record high, with Lidl notching up almost four million more customers than the previous year.

Lidl is currently Britain's sixth-largest grocery chain, according to experts at Worldpanel, after making the biggest market share gains in the sector in recent months.

Experts believe Lidl could overtake rival Morrisons, which is currently in fifth place, in the coming months if its current momentum continues.

Aldi is in fourth place for market share - behind Asda in third, Sainsbury's in second and Tesco in first.

Also this week, grocery prices across supermarkets in the UK in December were revealed to been 4.3 per cent higher than a year earlier - down from November's 4.7 per cent, according to Worldpanel.