US School Grade by Age: 2026 Quick-Reference Chart

In the US, kindergarten typically starts at age 5, and high school ends at 17–18. 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. The exact grade a child lands in depends on two things: their birthday and their state’s kindergarten age-cutoff date — most commonly September 1, though states range from June to October. Two children born a week apart can start school a full year apart if that week straddles the cutoff.

This guide gives the full age-to-grade chart, explains how state cutoff dates work, and includes grade-equivalent tables for the UK, China, Canada, and Australia.

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

What Age Is Middle School (Grades 6–8)?

Middle school covers ages 11–14 and introduces class schedules, subject-specific teachers, and a more independent workload. Some districts label this stage “junior high” and start it a grade earlier, at 6th grade instead of 7th.

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

GPA is one common way to track academic performance at this level, though not every US middle school calculates it. For the 4.0 scale, what counts as a good middle school GPA, and how to calculate it, see WuKong’s middle school GPA guide.

What Age Is High School (Grades 9–12)?

High school covers ages 14–18. Class-standing names (freshman, sophomore, junior, senior) carry over into 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

Families relocating to the US need the equivalent grade level for their child’s prior schooling.

What Is the China Grade Equivalent for US School Grades?

What Is the UK Year Equivalent for US School Grades?

What Is the Australian Year Equivalent for US School Grades?

What Is the Canadian Grade Equivalent for US School Grades?

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 mathematics education, including extensive hands-on experience preparing students for the SAT Math section. I believe that my professional expertise and refined teaching approach will allow me to make a meaningful contribution to the growth of Wukong Education. Within this community, I look forward to sharing insights on children’s educational psychology and effective learning strategies, with the hope of providing quality learning resources that help more children grow into confident, capable learners.