The typical age for students in each grade in the U.S. school system is approximately:

• Kindergarten: 5-6 years old
• 1st Grade: 6-7 years old
• 2nd Grade: 7-8 years old
• 3rd Grade: 8-9 years old
• 4th Grade: 9-10 years old
• 5th Grade: 10-11 years old
• 6th Grade: 11-12 years old
• 7th Grade: 12-13 years old
• 8th Grade: 13-14 years old
• 9th Grade (Freshman): 14-15 years old
• 10th Grade (Sophomore): 15-16 years old
• 11th Grade (Junior): 16-17 years old
• 12th Grade (Senior): 17-18 years old

Students may be slightly younger or older depending on when they start school and other factors like skipping or repeating a grade.