Cheapest supermarket in August: can Aldi beat loyalty scheme prices?

Aldi was the UK's cheapest supermarket in August – beating Lidl, Sainsbury's and Tesco, even when factoring in loyalty discounts.

We compared the prices of 62 popular grocery items and found that shopping at Asda was also cheaper than shopping at Tesco with a Clubcard or Sainsbury's with a Nectar card.

Read on to find out where was priciest, plus how the supermarkets compared for a mega trolley of 165 products.

Aldi prices beat Lidl Plus 

Every day in August, we checked the prices of 62 popular branded and own-brand groceries, including Heinz baked beans, milk and cheese, at eight of the UK's biggest supermarkets to see how they compared.

The chart below shows how much our shopping cost:

Aldi was the cheapest overall for our shop, beating rival discounter Lidl by £1.30 if you had a Lidl Plus card or £1.59 if not. 

Rolling in at £121.85, Asda also offered our list of groceries cheaper than Tesco with a Clubcard (£123.13). 

Sainsbury's was running Nectar price promotions on 17 items on our list, while Tesco had Clubcard prices on just four. Despite this, the Sainsbury's total with Nectar card (£123.75) was slightly more than the cost at Tesco even without a Clubcard.

• Find out more: cheapest supermarkets of 2024

Morrisons and Waitrose do also offer some loyalty prices to members of their schemes, but there were none for items on our shopping list this month. 

Waitrose was the priciest supermarket again this month, averaging £140.89 – that's £30.31 (27%) more than Aldi.

• Interested in more than just price? Shoppers have rated product quality, customer service, online deliveries and more to reveal the best and worst supermarkets

What about a bigger shopping list? 

When we looked at a much larger selection (165 items), including more branded groceries, the savings offered by the loyalty schemes were bigger. Asda, which doesn't offer loyalty prices, was still cheaper than Tesco and Sainsbury's though.

Sainsbury's Nectar – which offered loyalty prices on 86 of the items in our sample of 165 – was second.

Tesco offered Clubcard prices on 60 of the items at some point in the month and came third.

We couldn't include Aldi or Lidl here as they didn't stock all the branded items on our list.

These results show just how much more you'll pay if you stock up at Tesco or Sainsbury's without a loyalty card.

For shoppers without a Nectar card, Sainsbury's was second-most expensive after Waitrose. For non-Clubcard members, Tesco was just behind Ocado.  

• Find out more: how to spend less at the supermarket 

How much discount do loyalty cards give?

Based on our smaller list of products, having a loyalty card would save you 0.3% at Lidl, 0.4% at Tesco and 4.5% at Sainsbury's.

For our longer list, which included more branded groceries and a bigger selection of items with loyalty discounts, the savings were much more substantial – 5.5% at Tesco and 7.6% at Sainsbury's.

But you'd save even more money by switching to Aldi.

• Find out more: loyalty schemes compared

What's happening to grocery prices?

Grocery prices were 1.8% higher in the four weeks to 4 August 2024 compared to the year before, according to market analyst Kantar. That's the first time grocery inflation has increased since March 2023.

Prices are rising fastest for items such as vitamins, minerals, supplements, fruit juices and drinks, and chocolate. They are falling fastest for toilet tissues, bottled colas and dog food. 

• Find out more: Which? food and drink inflation tracker