If you have unopened boxes that are too small, most major retailers will let you exchange them for the next size up without a receipt, as long as they carry that brand.

Smaller packs are tempting for the lower "checkout price," but they usually have the highest PPU.

The golden rule of diapers is . Ignore the total price of the box; look at the tiny number on the shelf tag that tells you how much each individual diaper costs.

Amazon or Target subscriptions usually give you a 5–15% discount. This is the "peace of mind" tax.

Places like Costco (Kirkland), Target (Up & Up), and Walmart (Parents’ Choice) have stepped up their game. Kirkland, in particular, is legendary for being nearly identical to premium brands at a fraction of the cost.

Huggies and Pampers often have better elastic and specialized "pockets" for newborns. They are great for overnight use when you need 12-hour protection. 4. Subscription vs. Hunt

Diaper sizes overlap (e.g., Size 2 is 12–18 lbs, Size 3 is 16–28 lbs). If your baby is 17 lbs, move to Size 3.

Buying diapers sounds like a simple errand, but as any parent knows, it’s actually a high-stakes logistics operation. If you’re standing in the aisle (or scrolling through an app) feeling overwhelmed, " 1. The Math of the Bulk Buy