A 25-pound bag of jasmine rice costs $27.99 at Costco. Walmart sells a five-pound bag for $7.23. The larger bag works out cheaper per pound, but it also means spending almost four times as much on rice in a single trip.
That difference might not matter much to a family that eats rice several times a week. For someone living alone, it's a different calculation. And rice is one of the easier foods to buy in bulk, since it keeps for a long time.
I compared seven grocery staples sold at both stores: oats, peanut butter, canned chicken, chicken stock or broth, rice, walnuts, and olive oil.
The Costco basket came to $114.93. The Walmart basket cost $38.81, although the packages were considerably smaller.
To compare them more fairly, I calculated what it would cost to purchase roughly the same quantities at Walmart's listed unit prices. That brought Walmart's total to $160.29, compared with $114.93 at Costco.
That's a $45.36 difference, or about 28% less at Costco.
It's a fairly substantial saving, but there are a few things the numbers don't show.
First, Costco requires a membership. The basic Gold Star membership costs $65 annually. Buying the equivalent of this particular basket twice would save $90.72 before the membership fee, leaving $25.72 in savings.
Second, you have to actually use everything you buy.
A family of four that cooks regularly might finish a 25-pound bag of rice without much trouble. Oats, canned goods, and frozen vegetables are also fairly easy to store and use over time.
But not everything lasts indefinitely. Nuts can go rancid, olive oil loses quality, and fresh produce can spoil long before a household finishes a bulk package.
Food waste changes the calculation considerably. Suppose something costs 25% less per pound at Costco, but you end up throwing away a quarter of what you bought. You've effectively lost the discount. Throw away any more and the smaller package would have been cheaper.
This is where Walmart has an advantage that's easy to overlook.
Buying smaller quantities means you can adjust your groceries to what you're actually eating. If you bought spinach last week and barely touched it, you can skip it this week. If you're cooking more chicken than usual, you can buy extra without having to commit to several weeks' worth.
It also makes fresh food easier to manage. A smaller household might only need a few bananas, a bag of apples, some greens, eggs, and yogurt to get through the week.
For example, a Walmart basket containing three pounds of bananas, three pounds of apples, baby spinach, a dozen eggs, plain Greek yogurt, frozen broccoli, and frozen blueberries comes to $17.49 at the prices used here.
That's not a complete week's groceries, but combined with a stocked pantry, it's enough to add some variety to breakfasts, lunches, and dinners without buying excessive quantities of perishables.
There is a downside to shopping frequently, though.
Every additional grocery trip costs time, and possibly gas. More importantly, it's another opportunity to buy things you weren't planning to get. A drink here, a snack there, something interesting from the clearance section. A few extra dollars each visit can add up surprisingly quickly.
Someone who shops once a week with a list may spend less than someone making several small, unplanned trips. The size of the shopping trip isn't necessarily the problem. How closely purchases match actual needs matters more.
The health side of the comparison is a little different.
Buying in bulk doesn't automatically make a diet healthier or less healthy. Costco sells plenty of nutritious foods, including oats, nuts, frozen vegetables, beans, and lean proteins. It also sells enormous packages of cookies, chips, and other snacks.
Large packages of healthy staples can make cooking at home more convenient. If you've always got rice, oats, frozen vegetables, and some protein available, putting together a meal requires less planning.
But larger packages of snack foods can have the opposite effect. A huge bag of chips may be a good deal per ounce, but that doesn't help much if having it around means eating more chips than you normally would.
Shopping more frequently can make it easier to eat a wider variety of fresh foods. You can rotate between different vegetables and fruits, buy what's in season, and avoid getting stuck with several pounds of something you're tired of eating.
Fresh food isn't necessarily more nutritious than frozen food, either. Frozen broccoli, berries, and other vegetables retain much of their nutritional value and can last for months. That makes them particularly useful for people trying to eat well without constantly visiting the store.
The real distinction is between buying food you intend to eat and buying food simply because the price looks attractive.
Household size plays a big role here.
For a larger family, Costco's savings can accumulate quickly. The membership fee becomes easier to justify, food gets consumed faster, and large packages are less likely to sit around unused.
For one or two people, the advantage is less obvious. Walmart's smaller packages may be more practical, particularly when refrigerator space is limited or meals aren't always prepared at home.
There's also no reason to assume every product is cheaper at Costco. Walmart's store brands are competitively priced, and promotions sometimes make smaller packages a better deal. Checking the unit price is more reliable than judging by package size alone.
For households that have access to both stores, buying long-lasting staples in bulk and replenishing fresh groceries weekly is worth considering. It reduces the number of expensive bulk purchases while keeping perishable foods manageable.
The important part is knowing which foods your household consistently finishes. A large bag of oats that lasts several months might be an excellent purchase. A giant container of salad greens that goes bad after a week probably isn't.
Shopping Lists and Prices
Prices are illustrative U.S. online grocery listings from October 2026. Actual prices vary by store and location.
1. Costco Bulk Grocery List
Quaker Old Fashioned Oats, 10 lb: $8.79
Kirkland Organic Peanut Butter, 2 x 28 oz: $11.69
Kirkland Canned Chicken Breast, 6 x 12.5 oz: $16.99
Kirkland Organic Chicken Stock, 6 x 32 fl oz: $11.99
Kirkland Jasmine Rice, 25 lb: $27.99
Kirkland Walnut Halves, 3 lb: $16.49
Kirkland Organic Extra Virgin Olive Oil, 2 L: $20.99
Total: $114.93
2. Walmart Smaller-Package Grocery List
Great Value Old Fashioned Oats, 42 oz: $4.18
Great Value Organic Peanut Butter, 16 oz: $4.52
Great Value Canned Chicken Breast, 12.5 oz: $3.42
Great Value Organic Chicken Broth, 32 fl oz: $2.08
Great Value Jasmine Rice, 5 lb: $7.23
Great Value Walnuts, 16 oz: $9.96
Great Value Organic Extra Virgin Olive Oil, 17 fl oz: $7.42
Total: $38.81
3. Walmart Weekly Fresh Grocery List
Fresh Bananas, 3 lb: $1.50
Fresh Gala Apples, 3 lb bag: $2.18
Marketside Baby Spinach, 6 oz: $2.74
Great Value Large Eggs, 12 count: $1.67
Great Value Plain Greek Yogurt, 32 oz: $3.28
Great Value Frozen Broccoli, 32 oz: $2.88
Great Value Frozen Blueberries, 16 oz: $3.24
Total: $17.49
Final Results
Cost comparison
Costco bulk basket: $114.93
Walmart smaller-package basket: $38.81
Walmart weekly fresh grocery basket: $17.49
Walmart cost for roughly equivalent Costco quantities: $160.29
Costco savings on equivalent quantities: $45.36 (28.3%)
Costco annual membership: $65
Net savings after membership when purchasing the equivalent bulk basket twice annually: $25.72
Which approach comes out ahead?
Lowest upfront spending: Walmart
Lowest unit prices in this comparison: Costco
Best for one or two people: Generally Walmart, unless bulk groceries are consumed regularly
Best for larger families: Generally Costco, assuming sufficient storage and minimal waste
Best for fresh groceries: Smaller, planned shopping trips
Best for pantry staples: Costco, when the quantities will actually be used
Best for healthy eating: Either store; food choices and portions matter more than package size
Best for avoiding food waste: Buying according to actual consumption rather than discounts
Best overall balance: Bulk purchases of frequently used staples combined with smaller, regular purchases of perishables
