May's supermarket price comparison - who's cheapest?Find out which supermarket is cheapest this month
07 June 2014
We've calculated the price of a basket of branded food and grocery products, across supermarkets and found that Asda was the cheapest in May.
Asda charged an average £176.37 for the 82 items - at the other end of the scale Ocado charged £194.74 or £18.37 more.
Our basket includes between 80 and 100 products, averaged across the month, from the online supermarkets Asda, Tesco, Ocado, Sainsbury's and Waitrose. All the items are popular branded products from baked beans to toilet paper.
Which? members can log in to see how the other supermarkets compared, and how prices have changed over the last few months, on our supermarket prices compared page. If you're not already a Which? member, you can get instant access with a £1 one-month trial to Which? now. In order to work out the average price of our basket we used data from the independent shopping website mysupermarket.
Asda's market share has increased
Asda was the only major supermarket that saw its market share increase, in the last three months, according to Kantar Worldpanel.
Its figures show that the other three major supermarkets - Tesco, Sainsburys and Morrisons all saw their market share slip compared with the same time a year ago.
In contrast the discounters Aldi and Lidl continued to do well as did upmarket Waitrose.
At Which? we survey 11,000 people to find out how customers rate supermarkets for everything from trolleys to prices. Find out how the major supermarkets performed in our survey.
Supermarket price comparison schemes
If your shopping (or parts of it) would have been cheaper at another supermarket you may find that you are offered a voucher for the difference.
Tesco, Asda, Sainsburys and Ocado have schemes like this but the supermarkets they check against, the products they include and the terms differ. For example, Asda gives you a voucher if your shopping isn't 10% cheaper, Sainsbury's only compares branded products and Ocado only checks against Tesco.
Waitrose price matches Tesco on branded items and this is included in the total. Our comparisons include special offer discounts but not multibuys.