Find your current baseline
Add four to eight weeks of supermarket, convenience-store and food-delivery spending. Separate groceries from takeaways, alcohol, household products and toiletries if you want a clearer comparison.
Choose a first reduction you can sustain
If you currently spend £500 a month, jumping straight to £250 may fail. A smaller first target creates information: you learn which changes work without turning every shop into a battle.
Convert monthly to weekly
A weekly limit is easier to use while shopping. Keep a small portion back for milk, bread or genuine top-ups rather than spending the full amount on the main shop.
Attack waste before variety
Check the freezer, plan meals around existing food, use leftovers and freeze surplus portions. Cutting food that ends up in the bin can reduce spending without reducing what anyone eats.
Compare unit prices and alternatives
Promotions, larger packs and branded products are not automatically better value. Compare the shelf unit price, try own-brand alternatives and buy larger quantities only when you will actually use them.
Review after four weeks
If the budget worked comfortably, reduce it slightly or redirect the difference to savings. If it failed, identify why: unrealistic target, extra people, convenience shopping, waste, takeaways or items you forgot to include.