How Japanese School Grades Work: Lookup Table and Why April 1 Birthdays Fall a Year Ahead

One grade runs from April 2 to the next April 1

Japanese schools start in April and end in March. But the grade cutoff isn't April 1, it's April 2. People born from April 2 to April 1 of the next year share a grade, and children born on April 1 join the grade above.

Children born on April 1 and April 2 are one day apart but a whole grade apart. Within one grade there can be an age gap of up to 11 months and 30 days, which is where the discussion about haya-umare begins.

Why April 1 birthdays are a grade ahead

Japan's School Education Act says children start school at the beginning of the first school year after the day following the day they reach age 6. Combine that with the way age is calculated, in which a person gets a year older at the end of the day before their birthday, and the line falls at April 1.

1. 1

   Born on April 1

   The child reaches age 6 at the end of March 31, the day before their birthday. The following day is April 1. That April 1 is the "beginning of the first school year", so they start school that same April.

2. 2

   Born on April 2

   The child reaches age 6 at the end of April 1, and the following day is April 2. The school year has already begun, so the first school year begins on April 1 of the next year.

3. 3

   The result is one year's difference

   Children born in the same year on April 1 and April 2 start school a year apart. The child born on April 1 starts having just turned 6, and the child born on April 2 starts just before turning 7.

What being haya-umare actually changes

A gap of up to 11 months in one grade sounds large, but its effect varies a lot by age. There's no need to worry too much, though it's true the difference is easier to see in the early grades.

• Differences in size and development show most in the early elementary grades, and the relative gap narrows as children move up
• In sports divided by school grade, children born in April and May are known to be selected more often (the relative age effect)
• Milestone ages vary within a grade: in the winter of the third year of high school, when students sit entrance exams, there's a mix of 17- and 18-year-olds
• Haya-umare children spend a shorter time before starting work, so over the long run the gains and losses mostly cancel out
• Allowances and health checkups are often based on "age X at the end of the fiscal year" rather than grade, so check these separately

The last point is especially easy to miss. Notices for pre-school health checks and vaccinations arrive by fiscal year, so if you don't read whether they're based on grade or age, you may overlook something you qualify for. If a baby is due between late March and early April, the birth date decides the grade. To check the grade and maternity leave dates from a due date, see when maternity leave starts and how to calculate it from your due date.

Working out the grade from a birth date

1. 1

   Find the grade group's base year

   If the birth date is April 2 or later, the base year is that year. If it's April 1 or earlier, the base year is the previous year. Someone born on March 10, 2020 has a base year of 2019.

2. 2

   Find the entry year

   Elementary school starts in April of the base year plus 7. With a base year of 2019, that's April 2026. Junior high starts in April of the base year plus 13, and high school in April of the base year plus 16.

3. 3

   Find the current grade

   Subtract the base year from the current school year, then subtract 6. A result of 1 to 6 means elementary school, 7 to 9 means junior high and 10 to 12 means high school. The school year runs from April to March, so from January to March, use the previous calendar year as the school year.

4. 4

   Confirm with the tool

   Enter a birth date in the Age & Anniversary Counter and it shows "School grade (Japan, approx.)". Change the reference date to check the grade in past or future school years.

The steps are simple, but two points cause errors: treating January to March as part of the previous school year, and moving April 1 birthdays to the previous year. Get either one wrong and the result is off by exactly one grade.

Birth dates by grade in the 2026 school year

For the 2026 school year (April 2026 to March 2027), the table looks like this. It assumes standard progression through school.

Points to watch with paperwork

• The "grade" and "age" fields on a form are different. In the age field, write the actual age on the reference date
• Fare and ticket categories for cinemas and public transport are sometimes based on age rather than grade
• Many countries' schools start in September, which doesn't line up with Japanese grades. For transfers, the grade is decided by local standards
• The notice for the pre-school health check arrives in the autumn of the year before entry, when haya-umare children are still 5
• Repeated years or early university entry mean the grade from the birth date won't match, so use it only as a guide

The grade shown by the tool is also a guide based on standard progression. If you need to confirm the grade a child is actually enrolled in, check a document issued by the school, such as a certificate of enrollment. For everyday conversation or a rough sense of age, it's more than enough. How to calculate actual age from a birth date is covered in how to calculate age.

FAQ

Which dates count as haya-umare?

People born from January 1 to April 1 are called haya-umare. Those born from January to March share a grade with people born from the previous April 2, so they're the youngest group in their grade. April 1 birthdays are included in haya-umare.

Which grade do April 1 birthdays join?

The grade above. The child reaches age 6 at the end of March 31, the day before their birthday, and the following day, April 1 of the same year, is the beginning of the first school year, so they start school that April. Children born on April 2 start a year later.

Which children start elementary school in the 2026 school year?

Children born from April 2, 2019 to April 1, 2020. They enter elementary school in April 2026 and remain in year 1 until March 2027. Each school year, the whole range moves one year later.

Is being haya-umare a disadvantage?

In the early elementary grades, differences in size and development are more visible, and such children tend to be at a disadvantage in sports selection organized by grade. But the gap narrows as they move up, and starting work a year sooner brings an advantage, so over the long run the pros and cons mostly cancel out.