In the United States, the average age of a fourth grader is 9 years old. The age can vary depending on the child's birthday and date of entry into school.
When children follow the traditional elementary school course, they are 9 years old when they enter fourth grade. However, the current educational climate is changing, and more schools are offering transitional kindergarten programs to younger children. Most TK programs require students to be eligible for traditional kindergarten, but the programs are geared to those students who are on the younger end of the scale. If a child begins school in a TK program, he is likely to be 10 years old in fourth grade.