US: Size 3 to Europe Size 1
Cross-market children’s diapers, nappies, and training pants apparel conversion mapping Size 3 specifications into 1.

Analyzing Size Equivalence Across Markets
US: Size 3: Corresponds to a weight range of 7.3–12.7 (16–28 ) and an approximate age bracket of 6–12 .
Europe Size 1: Corresponds to a weight range of 2.5–4.5 (5–10 ) and an approximate age bracket of 0–1 .