A grocery budget compares what was bought, what was used and what was discarded. Record all three before deciding whether a cheaper package actually reduced the cost of a meal.
This guide provides a tracking method and fictional price examples. Replace the example prices with receipts from your own shops; they are not current market quotes or measured savings.
Start with the number you're already spending
People ask "what should a single person spend on groceries" as if there's an answer. There isn't. It depends on your city, how often you cook, and whether you count the $6 sandwich at lunch. So skip the benchmark and pull your own numbers. Go through the last two months of card and bank transactions and add up everything from supermarkets, corner stores, online grocery, farmers' markets, warehouse clubs. Keep restaurant and delivery spending in a separate pile. Both are "food," but they leak in different ways, and mixing them hides which one is actually the problem.
Fictional baseline: one household records $540 of monthly groceries, including $110 at convenience stores. These are assumed numbers used to demonstrate categorisation.
An example target of $460 would reduce that fictional $540 baseline by $80. Choose a feasible target after protecting adequate food and essential needs; 85 percent is not a universal rule.
Then break it into weeks. A month is about 4.3 weeks, so $460 becomes $107 a week. A monthly number is abstract by the 18th. "I have $31 left this week" is not abstract at all. Whatever you use to track it, a notes app, a budgeting app, a sticky note, the only requirement is that the weekly remainder is visible before you walk into the store.
Unit prices: the tiny print is the real price
Under nearly every shelf tag there's a smaller line: "$0.23/oz" or "$4.12/lb" or "$0.09 per count." This is the most useful information in the entire store and almost nobody reads it. Two boxes of the same cereal, 12 oz for $3.99 and 18 oz for $5.29: that's $0.33/oz versus $0.29/oz. The bigger box is 12% cheaper per ounce. Except if half the big box goes stale, your real unit price just doubled. The number that matters isn't price per ounce bought. It's price per ounce eaten.
The table below demonstrates unit-price comparisons with hypothetical prices. Recalculate from the products actually available to you.
| Item | Unit | Typical price | "Buy" threshold | Notes |
|---|---|---|---|---|
| Eggs | dozen, large | $3.89 | $2.99 | 18-pack only if I'll use them in 2 weeks |
| Milk | gallon | $4.29 | $3.49 | check the date; want 7+ days |
| Chicken thighs, boneless | per lb | $4.49 | $3.29 | portion and freeze same day |
| Rice, long grain | 5 lb bag | $6.99 | $5.49 | 20 lb bag only if pantry has space |
| Onions | 3 lb bag | $2.99 | $1.99 | bag is ~40% cheaper than loose |
| Canned tomatoes | 28 oz | $2.49 | $1.79 | stock up to 6 cans, no more |
| Olive oil | 1 L | $12.99 | $9.99 | I use ~1 L in 3 months; don't buy 3 L |
| Frozen peas | 16 oz | $1.99 | $1.49 | sale cycle about every 6 weeks |
| Greek yogurt | 32 oz tub | $5.99 | $4.49 | tub is half the price of cups per oz |
| Coffee, ground | 12 oz | $9.49 | $6.99 | freezes fine; buy 2 on sale |
With that table, "Buy 2 Get 1" and "Manager's Special" stop having any pull on you. If the sale price is above your threshold, it isn't a sale, it's just a yellow sticker on the regular price. And when a shelf-stable item drops below your threshold, rice, oil, canned goods, frozen vegetables, you can buy extra within the week's budget without any downside. "Extra" means two months' worth. Not six. Olive oil goes rancid, and a pantry full of bargains you can't reach is a different kind of waste.
Writing a list that starts in the kitchen, not the store
Everyone says "make a list." The part they leave out is the order of operations. A list written in the car on the way to the store is just a memory test, and you'll fail it.
Check refrigerator, freezer and pantry before writing the list. Plan meals around ingredients you can safely use, then add only the missing quantities.
Put quantities on the list. Not "onions" but "onions, 3." The quantity is what decides whether you buy the 3 lb bag or two loose ones, and without it you'll default to whichever is in front of you.
For an unplanned optional item, pause and check its purpose, price and whether it replaces something already on the list.
Choose a shopping time that works for your schedule. Buy marked-down food only if you can use or store it safely within its instructions.
A fridge inventory that takes two minutes
A simple inventory can have two sections: what is available and what needs using soon. Update it when shopping and cross off items as they are used.
Inside the fridge, two rules. Older stuff toward the front, new stuff toward the back, every time you unpack groceries. And one shelf at eye level is the "eat this week" shelf, where the three at-risk items from the list live. The crisper drawer and the back of the bottom shelf are where food goes to be forgotten. Only long-keepers go there: carrots, cabbage, whole citrus, hard cheese.
The freezer is its own problem. Because frozen food "doesn't go bad," it accumulates without limit until you're chiseling out a mystery bag from 2023. Tape and a marker: write the date on everything going in. Anything over three months old gets forced into that week's meal plan. And when the freezer is more than half full, that's a week where you buy no meat and no frozen anything. The $30 you'd have spent stays in the weekly budget, and the freezer gets a little air.
The waste that keeps happening
Review these possible sources of waste:
- **Big produce for one person.** A full bunch of kale, a family-size bag of salad, a whole head of celery. For a single cook, half of it wilts. The pre-portioned versions cost more per ounce but almost nothing goes in the trash, so the real cost is lower.
- **Aspirational groceries.** Avocados, sprouts, kefir, the ingredients for the healthy habit you're about to start. If the habit doesn't exist yet, the food gets tossed at an 80% rate. Build the habit with what you already eat, then buy the ingredients.
- **Duplicate condiments.** Two bottles of soy sauce, two unopened jars of the same mustard, three partial containers of sesame oil. This happens when you write the list without looking in the pantry first.
- **The "just grabbing something quick" tax.** A coffee and a breakfast sandwich at the corner store is $7. Five days a week is $140 a month. It's grocery spending, but it never feels like it, which is exactly why it needs to be tracked as its own line.
- **Confusing "best by" with "unsafe."** "Best by" is a quality estimate, not a safety limit. Yogurt, hard cheese, eggs, and most condiments are fine well past the date if they've been refrigerated. Learning to smell and look before tossing saves a surprising amount.
- **Free-shipping math.** Adding $14 of stuff you don't need to a $36 online order to unlock free shipping is paying $14 to avoid a $6 delivery fee.
- **Subscription deliveries that outlive the need.** A weekly produce box or milk delivery is convenient until your consumption changes and it doesn't. Only subscribe to things you consume at a fixed rate, and review it quarterly.
Splitting online and in-person shopping
Compare delivery fees, minimum orders, unit prices and expected waste when choosing online or in-person shopping. Neither channel is always cheaper.
Review an online cart before checkout. Remove duplicates and items with no planned use; do not assume a fixed saving percentage.
The first four weeks, in order
Trying to do all of this at once is how people quit by week two. Stage it. Week one: add up the last two months and set the weekly number. That's it. Week two: put the paper on the fridge and write down what's in there. Week three: start writing the list from the fridge, with quantities. Week four: build your unit-price table from the receipts you've collected.
At the next review, compare actual spending, food discarded and whether meals remained adequate. Adjust the plan using those observations; no reduction is guaranteed.
Tonight, one task. Open the fridge, find the three things that'll be garbage by Friday if you don't do something, and move them to the eye-level shelf. Tomorrow's dinner is whichever of those three you feel like.