The short answer
In most U.S. schools, a child's grade comes down to one date: the kindergarten cutoff. A child who turns 5 on or before the cutoff starts kindergarten that fall. Every year after that, they move up one grade.
So two children born a few days apart can land a full grade apart if the cutoff falls between their birthdays. That's the whole reason cutoff dates matter so much.
Age-by-grade chart
This chart assumes a rule of 5 on or before September 1 and no skipped or repeated years. Ages are at the start of the school year. A child born just before the cutoff is at the young end of each range, and one born just after is at the old end.
- Kindergarten: 5 to 6
- 1st grade: 6 to 7
- 2nd grade: 7 to 8
- 3rd grade: 8 to 9
- 4th grade: 9 to 10
- 5th grade: 10 to 11
- 6th grade: 11 to 12
- 7th grade: 12 to 13
- 8th grade: 13 to 14
- 9th grade: 14 to 15
- 10th grade: 15 to 16
- 11th grade: 16 to 17
- 12th grade: 17 to 18
How to find any child's grade
Start with the year the child first met the kindergarten rule. If their 5th birthday falls on or before the cutoff, that's the year they turn 5. If it falls after, it's the next year.
Then count forward. A child born August 15, 2019 turned 5 before September 1, 2024, so they started kindergarten in fall 2024 and will be in 5th grade in fall 2029. A child born September 2, 2019 missed the 2024 cutoff by a day, so they start in fall 2025 and reach 5th grade in fall 2030.
The same math works backward for "what grade was I in" questions. Someone born January 15, 1995 started kindergarten in fall 2000 under a September 1 rule, was in 5th grade in 2005-06 and in 12th grade in 2012-13.
Formula notes
Kindergarten year = birth year + 5 (birthday on or before the cutoff) or + 6 (after it)Grade in fall of year Y = Y - kindergarten year
Cutoff dates aren't the same everywhere
The September 1 rule is common but far from universal. The 2020 NCES table of state rules lists August 1 for Indiana and September 30 for Virginia, while New York, Ohio and Pennsylvania leave it to local districts. California law admits a child to kindergarten if they turn 5 on or before September 1.
Outside the U.S. the system can be different altogether. In England, most children start Reception in the September after they turn 4. Check the rule where your child will actually enroll. Our school age calculator checks a birth date against whatever rule you enter.
When a child doesn't follow the chart
Plenty of children sit outside the expected grade, and that's normal. Common reasons include:
- Families who hold a child back a year before kindergarten, often for a birthday close to the cutoff.
- Early entry, where a district allows it.
- Repeating or skipping a grade.
- Moving between states or countries with different cutoffs or grade names.
- Transitional or pre-kindergarten years that some states add before kindergarten.
Age is only part of the decision
The cutoff tells you when a child can start, not whether they're ready. Readiness covers physical, social, emotional and learning skills. If you're weighing whether to start on time or wait a year, talk with the child's preschool teacher and the school about the child in front of you, not just the birth date.
Frequently asked questions
What grade is a 10-year-old in?
Usually 4th or 5th grade in the U.S. With a September 1 cutoff, a child who turned 10 before the school year started is typically in 5th grade, and one who turns 10 during the year is in 4th.
What grade is a 7-year-old in?
Usually 1st or 2nd grade, depending on whether their birthday falls before or after the cutoff and when in the school year you ask.
What is redshirting in kindergarten?
It's the informal name for waiting a year to start kindergarten even though the child meets the age cutoff. It's most often considered for children with birthdays close to the cutoff.
How old is a child in Reception in England?
Most start Reception in the September after their fourth birthday, so they're 4 or 5 during the Reception year.
Can I find out what grade I was in a past year?
Yes. Work out your kindergarten year from your birthday and the cutoff, then count one grade per fall. It assumes you didn't skip or repeat a year.
References
These sources support the method or guidance used for School Age Calculator. Verify time-sensitive rules at the source.
Try the calculator
Open School Age Calculator, enter your scenario, and compare its supporting rows with this guide's method and checks.