Which is the cheapest supermarket in the UK?

The latest comparison checked for this guide

In Which?'s August 2026 comparison of 92 items, Aldi had the lowest average total. The leading three are shown below. The source page is dated 3 September 2026; these are August averages, not September checkout prices.

Which? combines branded and own-label products, averages daily prices, and uses fieldworkers where online prices are unavailable. Applicable loyalty prices and special offers count; multibuys, points and personalised rewards do not. The selected products can change, so monthly totals are not directly comparable.

Choose the shopping trip before comparing the shops

Write down what this trip needs to accomplish. A weekly shop for one person, a family freezer top-up and a small purchase after work involve different constraints. Decide your spending limit, how much you can carry, whether you have freezer space and when you can shop. A shop that suits one of those jobs may be awkward for another.

Shortlist the stores and delivery services available where you live. Retailer coverage, shop formats and delivery areas vary across the UK. Include any local independent shop that already works for you. Check the actual branch or postcode service instead of assuming a chain is available everywhere. A nearby store on an existing journey can deserve a place on your shortlist even when another retailer tops a national comparison.

Build one usable list

Choose a small set of meals before comparing prices. Then turn those meals into ingredients, combining duplicates into one quantity. If two dinners use onions, add the amounts together; if breakfast and lunch both use bread, work out how many slices you need. Check the fridge and cupboard first so the comparison covers purchases you genuinely need to make.

Keep that same list when assessing each shop. Changing from a large basket at one retailer to a smaller basket at another does not tell you which is cheaper for your plan. Where a product is unavailable, record an acceptable substitute and its full cost. If a missing ingredient means a second shopping trip, include that in the decision too.

Compare equivalent foods and pack sizes

A low shelf price can belong to a smaller packet. Compare the price per kilogram, litre or useful unit when products serve the same purpose. For example, an illustrative 500g pack at £1.20 costs £2.40 per kilogram; an illustrative 1kg pack at £2 costs £2 per kilogram. Those figures demonstrate the calculation and are not retailer quotes.

Make the comparison fair before choosing. Consider edible or drained weight where relevant, whether food is ready to eat or needs preparation, and whether the replacement suits your recipe. A dry ingredient and its cooked equivalent have different weights. A bone-in cut and boneless meat are different purchases. Read labels for ingredients and allergens instead of assuming two similarly named products are interchangeable.

Unit price answers one question: how much you pay for the quantity bought. It does not answer whether you can afford the larger pack today or use it before it spoils. A smaller pack can be the sensible purchase when it avoids waste or protects the rest of your budget.

Use the loyalty price you can actually claim

Record the regular price and any member price separately. Before counting a discount, check that you have the relevant account, can claim the offer through your chosen shopping method and are buying the eligible size or variant. Check the offer end date, especially when an online order will arrive later than the day you place it.

Keep money off today's bill separate from points, future vouchers and personalised rewards. They can all be useful, but they are different benefits. An offer that requires extra spending is only helpful if the extra products were already needed. Avoid adding a product merely to make the savings figure on an app look bigger.

Add the costs outside the basket

Make a second line beneath the grocery total for travel, parking, delivery or collection charges. If a delivery service has a minimum order or small-basket charge, check the terms for your proposed order. Use the final quoted checkout amount. A fee spread across several household shops is a different calculation from paying it for one small order.

Consider a simple invented example: Store A's groceries cost £28 with a £4 bus journey, while Store B's groceries cost £30 and it is on your walk home. On those assumptions, Store B costs £2 less overall. If the bus trip was already happening for another reason, the comparison changes. Use costs that apply to your actual journey.

Your time also matters, even when you do not assign it a cash value. Comparing three stores for every item can become a chore that stops you planning at all. Start with one main shop and investigate an alternative when a regular expense, such as a frequently bought staple, makes the effort worthwhile.

Give every perishable purchase a job

Before buying a large pack, name the meals it will go into and the day you will use or freeze it. Choose flexible ingredients that can appear in several dishes without making every dinner identical. Carrots might go into soup, a cooked vegetable side and a lentil sauce; a loaf can cover toast and sandwiches.

Check use-by dates, pack-opening instructions and freezer suitability. The lowest unit price becomes poor value if half the food ends up unused. Keep an easy meal available for evenings when plans change, and write that fallback into your list. A planned simple dinner is easier to budget for than an unplanned replacement shop.

After a week, review two things: what ran out and what remained. Adjust the next list using that evidence. You do not need to predict a perfect basket; you need a repeatable way to buy amounts that match your household.

Choose a repeatable approach

Try the same planning method for several shops. Keep receipts or a brief note of the final amount, your shopping method and any unusual purchase. A cupboard restock can make one week look expensive even though some of those ingredients will last. Compare like-for-like routines before deciding that a store switch has saved money.

Use BestBody's free grocery budget planner to divide your weekly amount across people and days. Price the actual ingredients and quantities using the retailer's current information, then review its final checkout total. Meal planning helps connect that shopping list to what you intend to cook.