No, 3T is not the same as 24 months. 3T stands for 3 Toddler and is a size designation used in clothing. It usually refers to clothes made for children between 2-3 years old, which would be about 24 months of age. This can vary slightly depending on the child's body type and growth rate, but generally speaking it ranges from around 18-36 months of age. On average though, 3T clothing should fit well up until your child reaches 36 months or so.