How to save on food shopping: unit prices, loyalty prices and downshifting

SYMUpdated Budgeting

The most reliable way to save on food shopping is a simple three-part system: compare products by unit price rather than pack price, only use loyalty prices on things you would have bought anyway, and downshift one brand level at a time to see what you can live with. Together with a list and a meal plan, these habits cut the bill without needing coupons or a dozen shops a week.

This guide explains each part with UK examples, then covers where you shop and how to lock in the savings.

Part 1: compare by unit price

Supermarket shelf labels show a unit price, such as per kilogram, per litre or per 100 sheets, alongside the pack price. It is the only fair way to compare pack sizes and brands, and it often reveals that bigger is not always cheaper, or that the multi-buy is worse value than the single large pack.

  • Look for the small print on the shelf label, or the price per kg in the online shop listing
  • Check the units match: some products are priced per 100g and others per kg, or per wash for laundry
  • Compare loose fruit and veg with pre-packed: loose is frequently cheaper per kilo and lets you buy only what you need
  • Check the world food aisle and the frozen aisle for herbs, spices, rice and vegetables, which can be much cheaper per kilo

Part 2: treat loyalty prices with care

Big supermarkets now show two prices on many items: a standard price and a lower price for loyalty card members, such as Tesco Clubcard Prices, Sainsbury's Nectar Prices and Lidl Plus offers. If you shop at those stores, joining is free and usually worth it. But a loyalty price is only a saving if you would have bought the item anyway.

  • Write your list first, then look for loyalty prices on it, rather than browsing for deals
  • Compare the loyalty price with the unit price of the own-brand alternative, which may still be cheaper
  • Ignore offers on things you do not normally buy, however good the percentage looks
  • Read our guide to supermarket loyalty schemes to see how points and prices work at each chain

Part 3: downshift one level at a time

Most supermarkets sell three tiers: branded, standard own-label and a value or basics range. Downshifting means trying one level cheaper for each product. If you cannot tell the difference, stay there. If you can, move back up. It removes the guesswork and stops a whole family revolting at once.

LevelExampleTypical result
BrandedBig-name cereal or pasta sauceHighest price
Own-label standardSupermarket's main rangeUsually noticeably cheaper
Value rangeBasics or budget lineCheapest; best for staples like tinned tomatoes, rice, flour

Staples such as tinned tomatoes, pulses, rice, pasta, oats, flour and frozen vegetables are the easiest place to start.

Where you shop matters

The gap between supermarkets is large. In Which?'s September 2026 analysis of 93 everyday items, the basket cost £159.48 at Aldi and £223.38 at Waitrose. You do not have to switch your whole shop: buying staples at a discounter and topping up elsewhere captures much of the difference. See our best value supermarket rankings for the full table.

Also look at reduced-to-clear shelves late in the day, apps such as Too Good To Go, and local markets for fruit and veg.

Plan before you shop

Planning stops impulse buys and food waste, which is money thrown in the bin.

  • Check the fridge, freezer and cupboards before writing your list
  • Plan four or five dinners a week around what you have and what is cheap, and leave room for leftovers
  • Cook once, eat twice: batch cooking is covered in our meal prep guide
  • Shop online if you overspend in store; you can see the running total and remove items before you pay
  • Freeze bread, meat and leftovers before they go off; our guide to reducing food waste has more ideas

Set a food budget and track it

Check your last two months of statements to see what you really spend on groceries, including top-up shops and meal deals, which are easy to miss. Set a weekly figure slightly below that, and record what you spend for a month. Our budget planner makes this easier. Move whatever you save each week into savings straight away, otherwise it tends to vanish. SYM can turn it into a daily habit with a suggested amount and one tap to log it.

If money for food is very tight, check whether you qualify for Healthy Start, free school meals or a food bank referral; our guide to help with food costs lists the schemes.

Frequently asked questions

What is the cheapest supermarket in the UK?
Aldi is regularly the cheapest in Which?'s monthly price comparison, and was cheapest in September 2026 with Lidl close behind using Lidl Plus. Prices change monthly, so check the latest results.
How do I compare supermarket prices properly?
Use the unit price on the shelf label or online listing, such as price per kg or per litre. It lets you compare different pack sizes and brands fairly.
Are loyalty card prices really cheaper?
They are cheaper than the same store's standard price, but not always cheaper than an own-brand alternative or another supermarket. Only count them as savings on items you would buy anyway.
Is own-brand food as good as branded?
Often it is very similar, especially for staples like tinned goods, pasta and frozen vegetables. Try downshifting one product at a time and move back up only if you notice a difference you care about.
How much should a couple spend on food a week in the UK?
There is no single right number, as it depends on diet, location and where you shop. Track what you spend for a month, then set a weekly budget slightly below it and adjust.
  • food shopping
  • groceries
  • supermarkets
  • unit pricing
  • loyalty cards