How to set a grocery budget for one person

Set a weekly food budget from your own receipts, then check that it covers the next restock as well as a cheaper shop. Shopping for one can make the amount hard to judge: a large pack lasts several weeks, while a small receipt may mean you're using food bought earlier.

Choose a starting amount for food

Start with several ordinary weeks of food spending. Check whether you ate enough and can replace what you used. Your dietary needs and cooking facilities matter more than matching someone else's receipt.

If you need a starting figure before you have records, try $110 a week and review it after three or four ordinary shops. That's about what a basic week of food costs one person, with a little room added; our 50/30/20 guide shows how it was worked out. It isn't a minimum or a target you need to force your shopping into. Stocking an empty cupboard may cost more at first.

Separate food from the supermarket total

Decide what you're counting before comparing shops. Here, groceries means food and non-alcoholic drinks bought for home or work. Household supplies and pets have their own amounts in the budget; bought lunches and takeaway sit under eating out.

The receipt below came to $110.90, but only $92.40 was food. The other $18.50 paid for dish liquid, toilet paper and cat food, which still need money elsewhere in the budget.

You can keep food and household items together if that's easier. Name the category clearly and use it consistently, so a restock of toilet paper doesn't look like a sudden rise in food spending.

Keep receipts for small top-ups too. Include cash purchases and subtract refunds. In a sharehouse, count your agreed share once, allowing for money housemates pay you back.

Include restocking in the average

Use six ordinary weeks of receipts for this exercise, or look further back if you've missed things you regularly buy. If purchases are spread across accounts, reviewing your spending helps bring them together without counting anything twice.

Add the food totals, then divide by the number of weeks covered. The example below totals $580 across six weeks, giving an average of about $97 a week. It includes a $127 restock in week three, after a cheaper week used food already in the cupboard.

A $100 weekly trial would set aside $600 across six weeks. Subtracting the $580 spent leaves $20. That's only a small margin, so check the next shopping list before settling on the amount.

Don't delete the expensive week to make the average smaller. Replacing staples is part of feeding yourself. Equally, check whether a low total came from meals elsewhere or finishing with a much emptier cupboard. Price the replacements before relying on that average.

Check what needs replacing

Look through the fridge, freezer and cupboard before writing the next list. You pay for a whole pack when you buy it, even if it lasts longer than a week. Using food you already bought doesn't count as another purchase.

You don't need to weigh everything. Notice the bigger replacements and whether your stock is broadly holding up. Keep enough grocery money available for those purchases rather than treating every cheaper shop as money freed up for something else.

Compare pack prices and unit prices

A unit price is the cost of a standard amount, such as 100 g or a litre. It lets you compare different pack sizes on the same basis. Check that the shelf tags use the same unit, then look at the full pack price too.

The tags below compare 1 kg of rice at $4 with 5 kg at $18. Divide each price by the number of 100 g portions: the small pack costs 40 cents per 100 g and the large pack costs 36 cents.

Five small packs would cost $20, so the large pack saves $2 for the same amount of rice. But buying it today costs $14 more than one small pack. Choose it only if you can use and store it while keeping the rest of the shopping funded.

The ACCC's unit-pricing guide explains how to compare similar products. A smaller pack can be the better choice when money is tight or a larger amount would be wasted.

Plan enough food until the next shop

Start with food that needs using, then list the missing ingredients for meals you'll have time to make. Include work lunches and nights when you'll get home late. Meals sharing an ingredient can help you finish a pack.

Keep unused grocery money for future restocking. If you set aside $100 this week and carried over $30, you have $130 for the next shop. That covers the example's $127 restock with a few dollars left. Spending the carried-over money elsewhere would leave the shop short.

If the list costs more than you have, review meals and pack sizes while keeping enough food in the plan. If there still isn't enough, Moneysmart, the government's free money guidance site, has an urgent-help page listing food-relief services and Ask Izzy, where you can look for local support.

Put groceries into the full budget

Check the trial amount alongside your other costs. Our guide to making a budget helps you plan for the whole pay.

For a monthly estimate, multiply the weekly amount by 52 and divide by 12. A $100 weekly grocery budget is about $430 a month, which is more than four weekly shops. Check the actual number of shops before your next payday too.

After several ordinary shops, compare what you spent with the food still available. If you stayed under the amount by skipping food or using up your stock, revise it. If meals and replacements are covered, you've found a more useful amount for the next plan.

A note from me

Shopping for one is fiddly. Most packs are sized for a family, and the cheap week often means you're eating last month's shop. Give your starting amount a few ordinary shops before deciding whether it fits.