Costco vs. Sam's Club vs. Walmart: Where Can You Save the Most?

We put three big grocery names side by side to see which store has the best deals.

As the cost of living continues to increase, one way to reduce your grocery bill is to shop around for the best prices. But sadly, comparing prices can be frustrating. Not only is it time consuming, the results don't always tell you much. They don't take into account specific offers in store, the extra cost of buying organic, and whether you buy store brands or shop in bulk.

To help you out, we compared prices on some common items such as apples, pasta, milk, and rice in Costco, Sam's Club, and Walmart. The results may surprise you.

Savings at Costco vs. Sam's Club vs. Walmart

To try to cut out some of the variables and actually compare apples to apples, we used the Instacart shopping app, as it let us line prices up against one another. However, if you're trying to cut costs, be aware that Instacart marks up prices quite significantly (one site estimated an average 15% markup), so using it isn't a good way to save money.

Caveats aside, Sam's Club came out ahead on almost every product. On a per-item basis, it cost around 25% less than Walmart and almost 10% less than Costco. Costco stands out for its organic fruit and vegetable offerings, but this also meant Sam's Club could squeeze its competitor cost-wise. Here's how the stores compare:

• Best for cost savings: Sam's Club
• Best for organics: Costco
• Best for non-bulk purchases: Walmart

Shopping around is not the only way to cut costs. Another is to make a commitment to cut food waste. About 30% of food gets thrown away each year, so freezing leftovers or making a weekly buffet meal of whatever's in the fridge could leave you with more money in the bank. There are also food waste apps that let you buy discounted food that would otherwise be thrown away. Finally, cash back apps can reward you for the spending you're already doing. You can stack rewards by also using a credit card that pays high rewards on grocery shopping.

Costco vs. Sam's Club vs. Walmart: Detailed price comparison

For each store, we've listed the Instacart price as well as the cost per pound or item. Walmart is more expensive on a per-item basis, but if you live alone or don't want to shop in bulk, it may be a more cost-effective way to shop. There's no point in buying a 10 pound bag of onions if you're not going to eat them all.

It's worth noting that you don't need a Costco or Sam's Club membership to use Instacart, but non-members pay more. This may have skewed our analysis, but it seemed fairer since not everybody is a member. We also took out some products because the items didn't lend themselves to a simple price comparison. For example, tuna didn't come in comparably sized cans, and it was hard to find similar types of bread.

Costco prices

Sam's Club prices

Walmart prices

Bottom line

One of the big takeaways from the tables above is the difference bulk buying can make to your per-item cost. Just make sure you'll actually consume those six pounds of chicken or pasta, otherwise it will wind up costing you more overall when you throw out uneaten food you paid for.

Do your own price comparisons on items you buy regularly. The Instacart app can help, but bear in mind that prices will likely be higher than the ones you'll find in store. Nonetheless, it makes a great starting point and shows that shopping around could cut your costs by as much as 25%.