US School Grade by Age: 2026 Chart, State Cutoff Rules & International Equivalents

In the US, most kids start kindergarten at 5 and graduate high school at 17 or 18. A 10-year-old is usually in 5th grade, a 12-year-old in 7th grade, and a 15-year-old in 9th or 10th grade. But the exact grade depends on your child’s birthday and your state’s enrollment cutoff date — which is why two kids born a week apart can end up a full grade apart.

This guide gives you the full age-to-grade chart, explains exactly how cutoff dates work state by state, and includes grade-equivalent charts for the UK, China, Canada, and Australia — useful if you’re relocating or comparing an international transcript.

US School Grade By Age: Quick-Reference Chart

This table covers the Average Age by School Grade from kindergarten to 12th grade. Save it for easy reference when planning school enrollment or transfers.

Ages reflect the age a student typically turns during that school year, not necessarily on the first day of school.

Online Tool: International Equivalents Grades

What Age Is Kindergarten in the US?

Most children start kindergarten at age 5. Whether a specific child qualifies depends on their state’s age-cutoff date — the date by which a child must turn 5 to enroll that fall.

According to NCES data on state education policies, cutoff dates cluster in a narrow window, most commonly falling between August 1 and October 1, with September 1 used by the largest number of states. A handful of states set the cutoff earlier (as early as June or July) or later (into October), and a small number leave the decision to individual districts rather than setting a single statewide date.

What this means in practice: a child born August 25 might start kindergarten at 4 (almost 5) in a state with an October 1 cutoff, while a child born September 5 in a September 1 state has to wait an entire additional year. Same age, different state, one full grade apart.

If you’re enrolling a child in a new state or district, the fastest way to get a definitive answer is your local district’s registrar — cutoff dates are set at the state level but sometimes adjusted locally, and the district’s decision is the one that actually matters for enrollment.

How Old Are You in Elementary, Middle, and High School?

US K-12 education is divided into three main levels, each with a standard age range.

Elementary School (Grades K–5): Ages 5–11

Elementary school builds foundational literacy and numeracy. Reading instruction typically shifts from “learning to read” to “reading to learn” around 3rd grade (age 8–9) — a milestone researchers and teachers treat as a key predictor of later academic performance.

• Kindergarten: 5 to 6 years old
• 1st Grade: 6 to 7 years old
• 2nd Grade: 7 to 8 years old
• 3rd Grade: 8 to 9 years old
• 4th Grade: 9 to 10 years old
• 5th Grade: 10 to 11 years old

Middle School (Grades 6–8): Ages 11–14

Middle school (sometimes “junior high,” which in some districts starts a grade earlier at 7th) introduces class schedules, subject-specific teachers, and more independent workload.

As students move through middle school, academic expectations also increase. GPA can be one way to track academic performance, although not every U.S. middle school calculates GPA. If you’re wondering how the 4.0 scale works, what counts as a good middle school GPA, or how to calculate it, see our guide to middle school GPA.

• 6th Grade: 11–12
• 7th Grade: 12–13
• 8th Grade: 13–14

High School (Grades 9–12): Ages 14–18

High school years carry class-standing names used in both school and — for freshman/sophomore/junior/senior — later in college.

• 9th Grade (Freshman): 14–15
• 10th Grade (Sophomore): 15–16
• 11th Grade (Junior): 16–17
• 12th Grade (Senior): 17–18

Why Kids in the Same Grade Aren’t Always the Same Age

A full birth-year can separate two students in the same classroom. The main causes:

1. State Cutoff Dates: The biggest factor. A child with a September 2nd birthday in a September 1st cutoff state will start school a full year later than a child born on August 31st.
2. Private School Flexibility: Private schools often have more lenient cutoff dates and may allow early or late enrollment based on individual readiness.
3. Gifted Students: Academically advanced students may skip a grade if they demonstrate mastery of current material and social maturity. IQ tests like the i-Ready diagnostic are important for identifying talents and guiding grade placement.
4. Delayed Enrollment (Redshirting): As mentioned earlier, many families delay kindergarten to give their child an advantage, especially in states with early cutoff dates.
5. Sports Redshirting: Some families delay enrollment so their child will be older and more physically developed for high school sports.
6. International Students: Students moving to the US from other countries may be placed in a different grade based on their previous education and English proficiency.

US Grades Compared to Other Countries

If you’re moving to the US from another country, use this guide to find the equivalent grade level for your child.

US vs China Grades

US vs UK School Years

US vs Australia School Grades

US vs. Canada

FAQs

Final Takeaway

Grade and age line up predictably in the US — kindergarten at 5, high school graduation at 17–18 — but your child’s exact placement depends on their birthday, your state’s cutoff date, and any school-specific evaluation. When in doubt, your local district’s enrollment office has the final, authoritative answer for your situation.

If your child is transitioning to the US school system or needs extra support to catch up or get ahead, WuKong Education offers personalized K-12 classes in math, English, and more. Our expert teachers adapt to your child’s grade level and learning pace, helping them thrive in any classroom. For independent practice at home, you might consider SplashLearn for game-based math and reading, Zearn Math for a blended curriculum, or Reflex Math for fact fluency.

Sources: National Center for Education Statistics (NCES) state education policy data; individual state departments of education. This guide is for general informational purposes — always confirm grade placement with your local school district.

Demi | WuKong Math Teacher

I am an educator from Yale University with ten years of experience in this field. I believe that with my professional knowledge and teaching skills, I will be able to contribute to the development of Wukong Education. I will share the psychology of children’s education and learning strategies in this community, hoping to provide quality learning resources for more children.