Kindergarten Age Cutoffs: How to Work Out When Your Child Can Start School

In the United States, most states require a child to reach a certain age, usually 5, by a specific "cutoff date" to start kindergarten that school year. Children with birthdays just after the cutoff wait another year, which makes them among the oldest in their class.

How cutoff dates work

A state might require children to be 5 on or before September 1 to enroll in kindergarten that fall. A child born on August 30 can start at just-turned-5; a child born on September 2 waits a year and starts at nearly 6. Cutoff dates vary by state, and in some states they're set by individual districts. Check your state department of education or local school district for the current rule.

Calculating eligibility

1. Find your state's or district's cutoff date for the school year you're considering.
2. Enter your child's birth date and the cutoff date in the chronological age calculator, using the "exact calendar" method.
3. If the result is 5 years 0 months 0 days or more, your child meets the age requirement.

Example: with a September 1, 2027 cutoff, a child born on September 1, 2022 is exactly 5;0.0 on the cutoff date and qualifies; a child born on September 2, 2022 is 4;11.30 and does not.

Early entry

Some states and districts allow early entry for children who miss the cutoff by a short time, sometimes after a readiness assessment. Policies vary widely; ask your district.

Academic redshirting

Some families choose to delay kindergarten for an eligible child, especially one with a summer birthday, to give them an extra year to mature. Research on the long-term effects is mixed, and the decision depends on the individual child. Talking with preschool teachers and your pediatrician can help.

Compulsory school age

The age at which school attendance becomes legally required is a separate rule, and in many states it's 6 or older. A child may be eligible for kindergarten before they're required to attend. Your state education agency publishes both ages.

Relative age in the classroom

Within one class, children's ages can differ by almost a full year. That matters for interpreting development and performance: a child born the day before the cutoff is almost a year younger than a classmate born just after the previous year's cutoff. This is one reason norm-referenced tests compare children by exact chronological age rather than by grade; see why exact chronological age matters.

Premature birth and school entry

School eligibility is based on the actual birth date, not corrected age. Parents of children born very early sometimes discuss delaying entry with their pediatrician; read about corrected age for context.