Aldi crowned the cheapest supermarket in March

Aldi is the UK's cheapest supermarket for the third month running in 2026, according to our latest analysis. 

Meanwhile, Asda has regained the top spot for our longer list of groceries in March, after losing out to Tesco in January and February this year. 

Read on to find out how other supermarkets, including Sainsbury's and Lidl, compare and how much you could save by switching supermarkets. Plus, we reveal the vegetable discounts to look out for this Easter.

Cheapest supermarket in March

We checked the prices of 95 popular branded and own-brand groceries, including milk, cheese and Hovis sliced bread, at eight of the UK's biggest supermarkets throughout March to see how they compared.

The table shows how much our shopping cost on average:

Aldi secured the cheapest supermarket title again in March, with an average price of £171.32 for our list.

Lidl, with Lidl Plus discounts, came second with an average price of £172.31 – only a 99p difference compared to Aldi. Without Lidl Plus discounts, the shop came to £172.41

Asda came in fourth with our list of items costing £193.37.

Tesco with a Clubcard at £198.07 was next, and cheaper than shopping at Sainsbury’s with Nectar (£199.79).

Morrisons was next with the items costing £201.02 on average throughout March.

Waitrose was again the most expensive supermarket in our monthly analysis, with the items on this list costing £235.70 on average. This is a difference of £64.38 or 37.6% compared to Aldi.

There were 41 loyalty discounts overall in March for our smaller list — 20 for Tesco, 19 for Sainsbury's and two at Lidl.

• Find out more: Cheapest supermarkets of 2026

What about a bigger shopping list?

Our longer list covers 223 items, including a wide range of brands not stocked at Aldi or Lidl, such as Heinz, Kellogg’s and Hovis. 

The table shows how much our shopping cost on average for the longer list:

Asda had the lowest average price for our longer list (£574.26) in March. 

Tesco with a Clubcard, came in second place with a cost of £584.95 – but if you didn't have a loyalty card, the same list would cost over £40 more.

Sainsbury’s with Nectar took third place, with the list costing £591.32 on average. Without Nectar, you'd pay nearly £47 more.

Waitrose was the most expensive shop for the longer list at £653.17 –  £78.91 more expensive than Asda.

There were 196 loyalty discounts overall in March — 103 for Sainsbury's, 91 for Tesco and two for Morrisons.

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

How much of a discount do loyalty cards give?

Based on our smaller list of products, having a loyalty card would save an average of 1.66% at Tesco, 2.71% at Sainsbury's and 0.06% at Lidl over the month.

For our longer list, which included more branded groceries and a wider selection of items with loyalty discounts, the savings were generally much more substantial – 6.42% at Tesco and 7.35% at Sainsbury's. However, savings were just 0.7% at Morrisons. 

The discounts offered by loyalty cards may sound good, but that's only if you can access them. Our research has found that millions of people can't access loyalty promotions because they're not eligible to join supermarket member schemes due to their age, lack of address or difficulties with digital access. 

In February, Tesco announced that it planned to make its Clubcard available to under-18s this year. The move comes after a major campaign launched by Which? urging supermarkets to lift their unfair restrictions on their loyalty schemes. 

Although this is a win for consumers, more work is needed as certain restrictions continue to lock people out of valuable savings. Groups often affected include those without smartphones and under-18s, who may struggle to access – or simply not know how to access – loyalty prices.

• Find out more: Loyalty schemes compared

What's happening to grocery prices?

The UK’s inflation rate remained at 3% in the year to February, according to the Office for National Statistics (ONS).

The largest upward driver was the price of clothing, but it was offset by the fall in petrol costs. However, the prices were collected before the start of the conflict in the Middle East and the subsequent rise in crude oil prices.

Numerator's latest grocery inflation figures held steady at 4.3% this month. However, experts warn that the Middle East conflict could drive this rate higher, with every 1% increase adding over £50 to the average household's annual shopping bill.

• Find out more: Check what's happening to prices by supermarket, category of food and ranges using the Which? food and drink inflation tracker

How Which? finds the cheapest supermarket

We check the prices of hundreds of grocery items at eight major supermarkets, using an independent price comparison website. 

For each supermarket, we calculate the average price of each item across the month, then add those up to get each supermarket's average total price. 

What items are on the list?

Our shopping list comprises the country’s most popular and widely available groceries, based on extensive market analysis. 

It includes branded items such as Cathedral City cheddar and Hellmann's mayonnaise, as well as own-brand products such as potatoes and baked beans. 

Own-brand items won’t be identical across supermarkets, but we’ve ensured everything we’ve compared is as similar as possible, based on several factors including quality and weight.

Which? never shares the full list of products used in its analysis, as we want to avoid any attempts by supermarkets to skew the results. 

We don't want supermarkets to compete with one another to lower prices only on the items they know they'll be judged on. Instead, we want retailers to work to make groceries affordable across the depth and breadth of their available lines.

What about special offers and loyalty prices?

We include special offers but not multibuy discounts. 

We are only able to include loyalty prices that apply to all members of a scheme (where there's one price on the shelf for shoppers with a loyalty card and another for those without). Currently, this type of two-tier pricing is used at Lidl, Morrisons, Sainsbury's, Tesco and Waitrose. 

We're unable to include discounts that are personalised to selected members, and we can’t factor in points or other rewards, as these vary between customers and don't always have a quantifiable monetary value.

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

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