Grocery Budget Calculator

Weekly grocery budget by household size depends on the number of people in the household, their ages (children vs. adults have different caloric needs), dietary preferences, and local cost of living. The USDA publishes monthly official food cost plans that provide evidence-based benchmarks by household type and income level.

What this calculator does:

Monthly Budget = Base per Person × Diet Factor × Household Factor × People

It works from one household average rather than summing individual ages, which is the trade-off that keeps it to two inputs.

Per-person cost scales non-linearly because larger households benefit from:

• Buying in bulk (lower per-unit costs)
• Reduced packaging overhead
• Shared staple ingredients

Household size, the USDA’s own adjustment:

The USDA prices its plans for a four-person household and then adjusts the total:

• 1 person: add 20%. Small packs, no bulk buying, and more produce goes off before it is eaten
• 2 people: add 10%
• 3 people: add 5%
• 4 people: no adjustment
• 5 or 6 people: subtract 5%
• 7 or more: subtract 10%

The curve flattens because staples scale and perishables do not. Past about seven people you are buying two of everything anyway.

The starting figure is $367.10 per person per month, the USDA moderate-cost plan for an adult aged 19 to 50 in August 2026 (the average of the $398.10 man and the $336.10 woman). The other plans for the same adult are Thrifty $286.30, Low-cost $296.45 and Liberal $457.50, and the panel shows all four.

A caution about the published USDA numbers. They are revised every month and they differ by age and sex: on the moderate plan an adult man costs about 18% more than an adult woman, and a primary-school child about a tenth less than the average adult. This calculator counts everyone as an adult rather than asking for ages, which is close enough for budgeting and wrong for anything official. The USDA publishes the current figures monthly, and they move with food inflation.

Worked example.

A family of four on a standard diet. Base is $367.10 per person per month and four people need no size adjustment, so the household total is $1,468 a month, or about $339 a week at the USDA’s 4.333 weeks to a month.

Switch that family to vegetarian and the factor of 0.92 brings it to $1,351. Switch to organic at 1.40 and it becomes $2,056. The diet setting moves the number far more than the household size does, which surprises people.

Bear in mind that the USDA plans are nutritionally adequate baskets cooked entirely at home, not a measure of what people spend. Real shopping runs lower. The average US household spent $6,224 on groceries in 2024, about $207 a person a month by the Bureau of Labor Statistics count, under even the Thrifty plan, partly because the same households spent $3,945 eating out. High cost-of-living cities add 20-40% on top of any of this.

One simplification worth knowing about: this page counts every person as an adult. That is fine for a household of grown-ups and it runs high for a family with small children. The family grocery budget calculator prices each person from the USDA table for their age instead, so two adults and two primary-school children come to $1,388 a month on the moderate plan where this page says $1,468, and it adds a region multiplier for outside the United States.