What size is after 4T?

After 4T, the next size typically is 5T or size 5, depending on the brand. "T" stands for "toddler," and the sizes may vary slightly between manufacturers. Size 5 is generally for children who are around 5 years old, while 5T is often meant for toddlers who are transitioning out of toddler sizes but not quite into regular children's sizes yet.