Quick answer: To find what discarded food costs your household, note each edible item thrown away for seven days, the amount lost and the price you actually paid. Add the value of only the discarded amount. Keep inedible peels and bones separate, change one habit, then repeat the diary in a comparable week. A UK average would not measure your own bill.
This method does not promise a fixed annual saving. A national waste statistic would not be a current price for your fridge, and a Swedish-krona headline cannot be converted into a reliable UK household estimate. Your receipts and what you discarded provide the relevant £ inputs. Do not multiply one unusual week into a guaranteed yearly saving.
AI-generated content. Always verify ingredients and allergen information yourself. A waste-reduction target never overrides food safety or a use-by date.
Keep a seven-day waste diary#
For one ordinary week, record food when you discard it. Note whether it was unopened, part of a pack or an uneaten cooked portion. Keep normally inedible scraps separate from edible food. Do not change all your habits during this first week; you need a useful baseline.
| Record | Amount discarded | Why it left the kitchen | Price to enter | Cost of edible waste |
|---|---|---|---|---|
| Half a pack of salad | Half the edible pack | Wilted before its planned meal | Your actual receipt price | Half that price, if the two halves are comparable |
| One of four cooked pasta portions | One portion | Not eaten or safely stored | The cost of ingredients used in the dish | One quarter of that used-ingredient cost |
| Banana peel | Inedible part | Normal preparation | Included in fruit purchase | Keep outside the edible-waste total |
These are worksheet examples, not observed household data or supermarket prices. For a discounted pack, use the amount paid after the real discount, not an old full shelf price. If you cannot establish the price, write “cost unknown” rather than inventing a national average. For a cooked dish, do not charge the entire week's shopping to one discarded portion; unused but still safe dry pasta remains available for another meal.
Keep the measurement boundary the same when you repeat the diary. Food eaten, given away or frozen for later is not discarded. A single unusual week multiplied by 52 is an extrapolation, not a measured annual loss. Guests, a holiday or a cancelled delivery can make two weeks poor comparisons.
Find the pattern before buying differently#
Group the edible-waste entries by their likely cause: too much bought, plans changed, wrong storage, an opened product forgotten, too much served or extra portions cooked without a safe use. These are prompts for your diary, not claims about the proportion of UK waste from each cause. Several may overlap; note the main one and any secondary cause.
| If your diary shows… | Try this next week | Check whether it helped |
|---|---|---|
| Salad or herbs wilt before use | Plan them for an early meal or buy a smaller suitable pack | Amount bought, eaten and discarded |
| A large pack is repeatedly unfinished | Compare a smaller pack or loose produce, including its whole price and unit price | Till bill as well as edible remainder |
| Cooked portions are left | Cook fewer portions or plan prompt chilling/freezing of an extra one | Portions cooked, eaten, stored and discarded |
| Opened tins or chilled foods are forgotten | Mark the opening date and follow the actual after-opening label | Opened packs used within their safe limit |
| A rigid menu collapses when plans change | Plan fewer fixed dinners and keep a cupboard/freezer fallback | Chilled food expiring before use |
Change one or two things first. If you simultaneously change shops, pack sizes, portions and storage, you cannot tell which change affected the diary. A lower waste weight alongside a higher till bill is not automatically a saving; nor is buying too little food for the household.
Keep the safety boundary clear#
Food Standards Scotland explains that use-by is about safety: food can look or smell fine after that date and still be unsafe. Best-before concerns quality, provided the product has been stored as directed. Always read the actual pack, including after-opening instructions. Do not use a sniff test to clear a food past its use-by date.
If suitable food is approaching its use-by date, cook or freeze it by that date according to its label; freezing does not repair food that was already unsafe. For cooked food, Food Standards Scotland's chilling guidance recommends a fridge at 0–5°C, cooling food without leaving it at room temperature longer than one to two hours, and eating ordinary refrigerated leftovers within two days. Follow a shorter pack instruction. Cooked rice needs separate, stricter handling; do not treat it as an ordinary leftover just to improve a waste figure.
Turn the diary into the next shop#
Choose your two largest avoidable entries and make each change specific. “Waste less salad” is vague; “buy one smaller pack and use it for the first planned dinner” can be checked. “Use the rest of an opened tin next week” is unsafe without its after-opening instructions; either name a timely second use or choose a different pack. Look in the cupboard and freezer before adding to the list.
The UK beginner meal-planning guide helps buy for dinners you expect to cook. This diary works in the other direction: it shows where your original plan differed from what actually happened. If a prepared meal was left, note whether the cause was recipe yield, appetite, a cancelled meal or unsafe storage; the next action differs.
Repeatable one-page audit#
- Keep receipts or record the price actually paid for relevant packs.
- For seven days, record the edible food discarded and its fraction of a pack or dish.
- Track inedible scraps and unknown prices separately.
- Calculate the value of discarded portions, not the cost of the entire shop.
- Identify one or two causes you can change without compromising food safety.
- Repeat the same diary on a comparable week, recording any unusual event.
- Report the observed difference in £ alongside what remains uncertain.
Can I claim a yearly saving from one better week?#
No. One week may be unusual. You could produce an explicitly labelled estimate from several representative weeks, but it remains an estimate rather than a guaranteed annual saving.
Should I keep food after its use-by date to reduce waste?#
No. Follow the safety date and storage instructions. Plan, cook or freeze suitable food by the date when the guidance and its pack permit that, and discard food whose safety cannot be established.
Sources checked 24 September 2026: Food Standards Scotland date-label guidance and chilling guidance. Any future UK-wide food-waste statistic or monetary figure needs its own directly checked source before being added.
Sources and further reading
- Use-by and best-before dates — Food Standards Scotland
- Chilling food — Food Standards Scotland