MoneyLion logo
Sign In
MoneyLion One
Loans
Credit Cards
Instacash
Credit Builder Plus
MoneyLion Spend
Managed Investing
Credit Monitoring
Budgeting
Games
Jul 28, 2026

Costco vs. Trader Joe's: Which Is Actually Cheaper for Weekly Groceries

Written by Kristen Mae
|
Edited by Rebekah Evans
Costco vs. Trader Joe's: Which Is Actually Cheaper for Weekly Groceries

If your goal is the lowest price per unit, Costco wins — but only if you can use what you buy. The warehouse giant's bulk format means dramatic per-pound savings on staples like chicken, coffee and butter, but those savings vanish if half the food goes to waste. Trader Joe's, by contrast, offers right-sized packages at prices that regularly beat conventional grocery stores, no membership required.

To find out which store actually saves you more money, we compared nine common weekly grocery staples side by side, using equivalent sizes or per-unit costs wherever possible to make the comparison fair. Costco prices reflect the Kirkland Signature house brand when available; Trader Joe's prices reflect their private-label equivalents. Find out below which store is actually cheaper.

Check Out: 8 Groceries To Grab at Costco Before Prices Spike This Summer

For You: 10 Things You Must Do When Your Savings Reach $50,000

Here's how each item stacked up.

Read This: The Best Costco Buys for the Money Right Now

Eggs

Costco wins by a wide margin — roughly $1.85 per dozen versus $6.99 at Trader Joe's, a difference of $5.15 per dozen. Keep in mind that Costco requires a two-dozen purchase minimum; for smaller households that can't go through eggs quickly, Trader Joe's single-dozen option is more practical even at a higher price.

Butter

Costco wins on a per-pound basis at $2.69 a pound versus $2.99 a pound at Trader Joe's — a savings of $1.67 per pound. Both products are comparable one-pound, four-stick packages; Costco simply bundles four pounds together for a better bulk rate. If you bake frequently or go through a pound of butter a week, the Costco pack pays off quickly.

Milk

Costco wins decisively at around $3.59 per gallon versus an implied $11.98-per-gallon equivalent at Trader Joe's — though it is worth noting the TJ's product is organic and from grass-fed cows, which commands a premium. For conventional whole milk by the gallon, Costco is the clear value play.

Coffee

Trader Joe's wins on per-pound price, coming in at roughly $6.75 a pound versus Costco's $8.60 a pound (a savings of about $1.85 per pound). Both are everyday ground coffees, and Trader Joe's wins without requiring you to buy three pounds at a time. Regular coffee drinkers who want bulk value should know Costco's price is still reasonable for the quality and quantity.

Olive Oil

Costco wins slightly on per-liter price at approximately $10.50 versus $10.99 at Trader Joe's, a difference of about 49 cents per liter. The Costco version is also certified organic and comes in a 2-liter container. Both are solid extra virgin olive oils and this is one of the closest matchups in the comparison.

Frozen Chicken Breast

Costco wins by a substantial margin: $2.99 a pound versus $7.49 a pound at Trader Joe's, a difference of $4.50 per pound. Costco's chicken is conventionally raised while Trader Joe's is certified organic and free range, which explains some of the price gap. For households buying chicken weekly, Costco's bulk packs can be portioned and frozen at home for significant annual savings.

Snacks

Trader Joe's wins on snack price: the iconic peanut butter pretzel nuggets come in at roughly $2.69 a pound versus Costco trail mix at around $4.25 a pound. These are different snacks, and Costco's trail mix includes almonds, cashews, M&M's, and raisins, making it a more complex product. Still, for casual snacking, Trader Joe's offers more per dollar.

Bananas

Trader Joe's wins narrowly on bananas at roughly 46 cents a pound versus Costco's 56 cents a pound, though the difference is minimal (just a few cents per pound). Trader Joe's per-banana pricing is especially useful for solo shoppers who only want two or three at a time, while Costco's bag forces you to buy a full 3-pound bunch.

Bread

Trader Joe's wins at $2.29 per loaf versus roughly $3.25 per loaf at Costco. Costco does require a two-loaf purchase; if your household goes through bread quickly, the per-loaf price difference is modest. But for smaller households that might not finish two loaves before they go stale, Trader Joe's single-loaf purchase is the smarter buy.

Overall, Costco is the better deal for households that can use bulk quantities — especially on eggs, butter, milk, chicken, and olive oil, where the per-unit savings are real and substantial. Trader Joe's edges ahead on coffee, snacks, bananas, and bread, and wins outright for anyone who doesn't want a warehouse membership or to buy in bulk. For a family of four that goes through staples quickly, shopping Costco for proteins, dairy, and oils while hitting Trader Joe's for snacks and bread is the smartest hybrid strategy - and could save you well over $50 a month.

Editor's note: Prices and availability are subject to change.

More From MoneyLion:

More From MoneyLion:

This article was provided by MoneyLion.com for informational purposes only and should not be construed as financial, legal, or tax advice. It was created with the assistance of artificial intelligence and reviewed by our editorial team for accuracy; however, AI-generated content may be inaccurate, incomplete, or outdated. You should independently verify important information through reliable sources before making any decisions based on this content.

Written by
Kristen Mae
Edited by
Rebekah Evans