Aldi named the UK's cheapest supermarket for the fifth month running

Aldi has once again come out on top in the monthly battle of the supermarket tills, holding on to its title as Britain's cheapest grocer for the fifth month in a row, according to the latest research from consumer champion Which?. The result underlines just how firmly the German discounter has established itself in the value stakes, at a time when households remain acutely sensitive to the price of the weekly shop.

For its May comparison, Which? tracked the cost of 95 popular branded and own-brand items, from milk and cheese to Hovis sliced bread, across eight of the country's biggest supermarkets. The same trolley came to £168.30 at Aldi, the lowest of the lot, and a sum that left the traditional supermarket chains trailing in its wake.

The findings will be welcome reading for shoppers determined to stretch their budgets further, and another reminder that where you choose to shop can make a striking difference to how much you pay for broadly the same goods.

How the supermarkets stacked up

Lidl, with its Lidl Plus loyalty discounts applied, was hot on Aldi's heels at £170.58, leaving the two German discounters well clear of the traditional big four. The widest gap was at the premium end: Waitrose came in at £235.49, a hefty £67.19 more than Aldi, or close to 40% pricier for the same shop. For a family doing a comparable shop every week, that difference adds up to thousands of pounds over the course of a year.

• Aldi: £168.30
• Lidl (with Lidl Plus): £170.58
• Asda: £192.58
• Tesco (with Clubcard): £196.88
• Morrisons: £197.50
• Sainsbury's (with Nectar): £198.79
• Waitrose: £235.49

Loyalty schemes made a noticeable difference at some chains. Which? found Sainsbury's Nectar members shaved 3.58% off their bill and Tesco Clubcard holders saved 2.67%, while the Lidl Plus discount was marginal at just 0.05%. The growth of members-only pricing has become a defining feature of the modern supermarket landscape, with the big chains increasingly using digital loyalty schemes to compete on headline prices.

Consumer groups have noted that while these schemes can deliver genuine savings, they also reward shoppers who are willing to sign up, share their data and keep track of personalised offers. For those who prefer not to, the simplicity of the discounters' flat low pricing remains a powerful draw.

“Month after month the discounters keep their lead, but loyalty pricing means the gap at the big chains is narrower than the shelf-edge labels suggest.”

— A consumer affairs analyst

How the comparison works

Which? conducts its supermarket price comparison every month, building a basket of widely bought groceries and recording what each store charges for like-for-like products. Because Aldi and Lidl carry smaller ranges and stock fewer branded lines, the consumer group uses a separate, larger basket when comparing the big supermarkets against one another, ensuring the figures reflect genuinely comparable shopping.

The methodology is designed to give shoppers a fair, repeatable snapshot of where the best value lies, rather than cherry-picking individual deals. Over time, the monthly results have become a closely watched barometer of competition on the high street and a useful guide for households trying to keep costs down.

Background and context

The cost of living squeeze of recent years pushed grocery prices firmly up the list of household concerns, and although headline food inflation has eased from its peaks, many shoppers say their bills still feel stubbornly high. That backdrop has accelerated a long-running shift towards the discounters, which have steadily expanded their store networks and grown their share of the market.

The established chains have responded with price-matching pledges, loyalty discounts and expanded value ranges, but the discounters' lean operating model continues to give them an edge on price. Their narrower ranges and limited branded choice remain the trade-off for shoppers seeking the lowest possible bill.

Part of the discounters' advantage lies in how they run their stores: smaller ranges mean simpler logistics, fewer staff are needed to keep shelves stocked, and many products are sold in their delivery packaging rather than being individually arranged. Those efficiencies translate directly into lower prices, and they are difficult for the larger chains, with their wider ranges and more elaborate store formats, to match without fundamentally rethinking how they operate.

What it means for shoppers

The result continues a run of dominance for Aldi, which topped the table for 10 of the 12 months in 2025, beaten only by Lidl in July and October. With household budgets still under pressure, the message for shoppers chasing value remains a familiar one: the discounters are tough to beat, though their narrower ranges and limited branded choice are the trade-off. For many families, the savviest approach may be a hybrid one, doing the bulk of the shop where it is cheapest and topping up elsewhere for the specific brands they cannot do without.