Consumer group Which? has identified Waitrose as the UK supermarket with the fastest-rising food prices, recording an annual inflation rate of 3.8% for the three months to the end of May 2026. In contrast, Aldi had the lowest inflation at just 0.8% for the same period, according to the watchdog's supermarket inflation tracker.
How the Inflation Tracker Works
Which?'s tracker, the first publicly available tool of its kind, analyses prices across 20 popular food and drink categories at eight major supermarkets: Aldi, Asda, Lidl, Morrisons, Ocado, Sainsbury's, Tesco, and Waitrose. It compares prices over the same three-month and one-month periods year-on-year, including discounts but excluding multibuys or loyalty card offers. The group weights the figures based on supermarket market share and the sales volume of each product category.
For the month of May 2026, Waitrose's annual inflation stood at 3.8%, while Aldi's was 0.8%. The full list of supermarkets ranked by inflation rate for May 2026 is as follows: Waitrose 3.8%, Sainsbury's 3.6%, Tesco 2.9%, Asda 2.3%, Ocado 2.0%, Lidl 1.4%, Morrisons 1.1%, and Aldi 0.8%.
Inflation vs. Absolute Prices
Which? noted that inflation measures how quickly prices are rising or falling, not the absolute price level. This means supermarkets with the highest inflation could still be among the cheapest overall. The food categories with the fastest-rising inflation included fish, energy drinks, fizzy drinks, water, savoury pies, pastries and quiches, and fresh fruit.
Impact of the Strait of Hormuz Crisis
Experts have warned that the ongoing conflict in Iran and the Strait of Hormuz crisis could have a delayed effect on food prices. Jonathan Owens, a supply chain expert and senior lecturer at the University of Salford, told The Independent that the conflict may lead to higher fertiliser costs for farmers, pushing up the price of staples like bread, pasta, and cereal. "Rising costs and shipping delays could disrupt planting and harvesting cycles if this plays out for the long term," he said. He added that increased feed prices could also pressure meat and dairy production.
