WEBDec 2, 2023 · If you look at baby shoe sizes, US Sizes 4C (child) size shoes and 4T (toddler) are the same. If you’re wondering what size shoe a one-year-old wears, measuring their foot is best. A 12-month-old wears a size 3, 4, or 5. An 18-month-old wears a size 4, 5, or 6. Use my printable (or print-free) instructions below.