Size 3 Diapers Market Report: Sales Volume, Market Share, Leading Brands & Market Trends

HUGGIES is the best-performing size 3 diapers brand in July 2026, moving 148,000 units across 4 ASINs for 76.3% of Top 10 volume. Pampers follows with 26,000 units (13.4%), ahead of Pull-Ups on 7,000 units (3.6%).

With 5 brands splitting the Top 10 and 93.3% of volume sitting with three of them, this is a concentrated shelf — the leaders hold multiple listings or one very high-velocity ASIN, so a new entrant competes against established review moats rather than an open field. Average selling prices among the leaders run from $26.49 to $43.15, which frames the price band a competing listing has to justify.

Based on July 2026 data, this shortlist surfaces the two kinds of ASIN worth keeping an eye on — the ones that just broke into the Top 10, and the ones growing fastest month over month. On the growth side, B082QBFMSY leads positive momentum with ▲ 50.0% MoM growth on 3K units, with B09MX7YGLX close behind at ▲ 50.0% MoM on 3K units.

The two signals carry different weight. A fresh entrant means share has already changed hands — an incumbent gave up its place to make room, so any competitive set drawn up a month ago is now out of date. A steep growth rate works as the earlier warning: it marks demand that is still compounding, usually a month or two before the ranking catches up to it.