Grocery budget: find your real number, then lower it

Step 1: find your real number

Look back over the last four weeks. Using receipts, your bank app or your card statements, add up every purchase at grocery stores, markets and warehouse clubs. Then take out anything that is not food you eat at home: cleaning supplies, toiletries, alcohol if you budget it separately, and prepared meals if you count them as eating out. What remains is your grocery spending.

Four weeks gives a much better picture than one, because grocery spending is lumpy: one big stock-up trip, a few small ones, a week where you barely shopped.

Step 2: convert it properly

A month is about 4.33 weeks, not four. To turn a weekly average into a monthly figure, multiply by 52 and divide by 12. Using four weeks per month understates monthly spending, which is one reason grocery budgets often fail.

Step 3: compare with a benchmark

The USDA publishes monthly reports estimating what it costs to eat a nutritious diet at four levels, the Thrifty, Low-Cost, Moderate-Cost and Liberal food plans, broken down by age and sex and for sample households. These are national averages and assume all meals and snacks are prepared at home, so your local prices may be higher or lower. If your spending is well above the Moderate-Cost figure for someone like you, there is probably room to cut; if it is near the Thrifty level already, focus on reducing waste rather than spending less.

Step 4: cut in ways that last

Small, repeatable changes beat dramatic ones you abandon after a week:

• Plan three dinners and build the list from them, then fill gaps with leftovers and pantry meals.
• Check what you have before shopping. A photo of the fridge on your phone works.
• Compare unit prices on the shelf tag, the price per ounce or per count, rather than package prices.
• Try store brands for staples like rice, canned tomatoes, flour and frozen vegetables.
• Buy produce you will use this week, and lean on frozen fruit and vegetables for the rest; they keep for months.
• Cut waste. Food you throw away is money spent for nothing. Freezing leftovers and using older items first often saves more than coupons.

Step 5: track one month and adjust

Keep receipts for the test month and check your total weekly. If you hit the target easily, keep it and consider a further small cut. If you missed it, look at where: one big trip, lots of small trips or a few expensive items. Adjust the target or the habit, not your whole diet. The goal is a number you can hit most months without feeling deprived.

Shopping for more than one

If you shop with a partner or roommates, decide which items are shared and how they are split. Some households pool money for staples and buy personal items separately. The calculator's per-person line divides the monthly target by the number of people, which is a starting point; adults with different appetites or diets may agree on a different split.

A note on cheap and healthy

Spending less does not have to mean eating worse. Staples such as dried or canned beans, lentils, oats, rice, eggs, frozen vegetables, bananas and carrots are usually inexpensive per serving and keep well, which makes them a good base for low-cost meals. Building a few meals around them, and adding fresh produce you will eat that week, keeps both the bill and the waste down.