BJ’s vs. Costco vs. Sam’s Club: A Mom’s Guide to Buying Diapers, Formula, and Baby Gear

If you’re a mom like me, you know one thing: babies somehow go through more diapers and formula than seems physically possible. When my kids were younger and I first started stocking up, I had no clue which wholesale club would actually save me the most—and after a few too many frantic diaper runs, I decided it was time to figure it out for real.

I’ve been shopping at all three for years: BJ’s, Costco, and Sam’s Club. And after plenty of full carts and “oops, wrong size” returns, I can tell you—each one has its sweet spots. Whether you’re trying to keep a nursery stocked, score affordable formula, or snag a deal on a stroller, here’s how they really stack up when it comes to baby essentials.

Diapers: Store Brands vs. Name Brands

When it comes to diapers, I found that warehouse clubs can make or break your budget depending on what you need—and how brand-loyal your baby’s bottom happens to be to a particular brand. This was hard with my daughter as she had very sensitive skin where as my boys could wear most anything.

• Costco: Kirkland Signature diapers have a near-cult following for good reason. Honestly, they’re fantastic—super absorbent, great fit, and pretty much leak-proof. Rumor has it they’re made by the same manufacturer as Huggies. If you’re okay without Pampers (Costco doesn’t stock them), you can save big, especially when Costco runs its famous instant savings.
• Sam’s Club: Member’s Mark diapers are slightly cheaper and still pretty solid. Sam’s has a slight edge if you want more choices—you’ll find both Huggies and Pampers stacked high. Plus, they often throw in extra savings through Instant Savings events, which makes restocking a little less painful.
• BJ’s Wholesale: BJ’s shines for flexibility. They sell all the big brands—Huggies, Pampers, Luvs—and their own Berkley Jensen line. And here’s the best part: BJ’s lets you stack manufacturer coupons on top of in-club deals. If you’re into serious savings (and don’t mind a little couponing homework), BJ’s can come out cheapest of all.

I preferred Costco when I wanted worry-free quality, Sam’s if I was chasing name-brand deals, and BJ’s when I had extra time or was in full-on budget mode and feeling like a coupon ninja.

Explore More: BJ’s vs. Costco vs. Sam’s Club: Which Wholesale Club Is Best for Groceries and Household Essentials?

Formula and Feeding Essentials

Formula feeding mamas, I feel you—those costs add up fast. And the warehouse clubs approach formula very differently.

• Costco’s Kirkland ProCare Formula is basically Similac Pro-Advance… for half the price. I switched to it with my second child, and no regrets. If your baby tolerates standard formula, this is one of the best deals anywhere.
• Sam’s Club stocks a wide range, including Enfamil and Similac varieties you might not find at Costco. Their store-brand formula is wallet-friendly, but the real win here is having lots of options for sensitive tummies, ready-to-feed bottles, and specialty blends.
• BJ’s Wholesale hits a sweet spot: they carry a good store-brand formula (Wellsley Farms) and all the big brands. Plus, because BJ’s takes manufacturer coupons, you can double-dip savings—something I definitely took advantage of when formula checks showed up in the mail.

Again here Costco was my choice for standard formula savings. Sam’s had more specialty options. BJ’s was the leader if you love coupons and flexibility.

Baby Gear: Strollers, Car Seats, and More

Now for the bigger stuff—gear! If you’re hunting for a deal on cribs, car seats, or baby monitors, here’s the lay of the land:

• Costco stocks fewer brands in-store but has a surprisingly good online selection of strollers, travel systems, and nursery furniture—all with Costco’s epic return policy as backup. I bought my daughter’s convertible car seat at Costco.com after comparing prices everywhere, and it was a total steal.
• Sam’s Club offers more options both in-store and online. I was surprised by how deep their online inventory goes—cribs, monitors, bassinets, even 4moms swings. Plus, Sam’s occasionally bundles extras (like a second car seat base) for free.
• BJ’s Wholesale is a little lighter on the big gear in-store but makes up for it online. If you’re hunting for essentials like high chairs or play yards—and love stacking BJ’s coupons—BJ’s can score you a serious bargain.

Costco if you want total peace of mind. Sam’s if you want one-stop-shop variety. BJ’s had some great deals, but you have to love hunting down that deal online.

Shopping Experience: Ease, Delivery, and Curbside

Here’s where my life with a baby really meets reality: how fast can you get in, out, and get home before everything comes unglued?

• Sam’s Club Scan & Go is a gift from the heavens. I can scan diapers as I toss them into the cart, pay on my phone, and skip the checkout line entirely. Plus, Sam’s offers free curbside pickup for Plus members.
• BJ’s ExpressPay works similarly, and they also offer free curbside pickup, even with manufacturer coupon stacking—huge if you want speed and savings.
• Costco, bless them, still makes you stand in line. They’re adding more self-checkout lanes lately, but no Scan & Go app yet. Delivery is available (via Instacart for same-day), but it’s extra.

For true grab-and-go shopping with a baby in tow, Sam’s wins by a landslide. BJ’s is close behind. Costco… well, it’s still Costco: busy, bustling, but beloved.

Explore More: BJ’s vs. Costco vs. Sam’s Club: A Mom’s Guide to Choosing the Best Wholesale Club Membership

Final Verdict: Which Club Wins for Baby Essentials?

Choose BJ’s if you love stacking savings and want flexibility on brands and pack sizes.
Choose Costco if you want premium-quality diapers, wipes, and formula—and unbeatable return policies.
Choose Sam’s Club if you crave convenience, fast shopping, and lots of baby options under one roof.

If you live near more than one, seriously consider having memberships to two clubs. I do—Costco for my staples, Sam’s and BJs for those times when I need to swoop in quickly and grab something specific.