Preschool age calculator: when will your child start preschool and kindergarten?
Preschool age calculator
Enter your child’s birthday and your state to see the year they start preschool, pre-K and kindergarten, and how old they will be on the first day.
How old are children in preschool, pre-K and kindergarten?
In the United States, children usually start preschool at 3, move to pre-K at 4, and start kindergarten at 5. Kindergarten is the first year of elementary school. The exact year depends on where your child's birthday falls against your state's cutoff date, which is what the calculator above works out for you.
| Stage | Typical age | What it is |
|---|---|---|
| Preschool | 3 to 4 | The first year of early education, often two or three mornings a week. |
| Pre-K (pre-kindergarten) | 4 to 5 | The year right before kindergarten. In California this is called transitional kindergarten, or TK. |
| Kindergarten | 5 to 6 | The first year of elementary school. Compulsory in about a third of states. |
| First grade | 6 to 7 | The year after kindergarten. Compulsory everywhere. |
How the calculator works
Every state sets a date by which a child must turn 5 to start kindergarten that fall. Most use September 1, but the range runs from June 30 in West Virginia to October 15 in Maine, and eight states leave the date to each school district, some of which go as late as December 31. The calculator checks your child's fifth birthday against your state's date, finds the kindergarten year, then counts back two years for preschool and one for pre-K.
Two children born a day apart can end up a full school year apart. A child born on September 1 in Texas starts kindergarten the fall they turn 5. A child born on September 2 waits until the following year and starts at nearly 6.
Check with your district if the result matters. The dates here are the state rules for the 2026-27 school year. Districts in states without a statewide date can differ, and a few states offer early entrance by assessment. Public pre-K and Head Start use the same cutoff as the local kindergarten. Private preschools set their own dates and often take younger children.
What if the birthday is close to the cutoff?
If your child's birthday falls in the two months before the cutoff, they will be one of the youngest in their class. Waiting a year, often called redshirting, is legal in every state and common for summer birthdays, especially for boys. It is not automatically better. Older children tend to have an edge in the first year or two, and that edge fades by the middle grades.
If your child misses the cutoff by a few days, they will be one of the oldest in their class the following year. A few states, including Arizona, Illinois and Minnesota, let districts admit a younger child after an assessment, but most do not, and most districts advise against it even when it is possible.
Preschool, pre-K, TK and kindergarten: what the names mean
Preschool is the general term for education before kindergarten, usually ages 3 to 5. Pre-K is the preschool year for 4-year-olds, and is often run by public schools. Transitional kindergarten, or TK, is California's version of pre-K, and since 2025 it is open to every child who turns 4 by September 1. Kindergarten is the first year of elementary school. Outside the US the word kindergarten often means preschool, which is why families who have moved from abroad find the American system confusing.
Is preschool required?
No. Preschool and pre-K are optional everywhere in the US, although many states now fund free pre-K places. Kindergarten is compulsory in only about a third of states. In the rest, school attendance becomes compulsory at 6 or 7, and at 8 in Washington, but almost all children still attend kindergarten at 5 because first grade assumes it.
Keep reading
Common questions
What age is preschool?
Preschool covers ages 3 to 5 in the United States. Most children start a preschool program at 3, move to pre-K at 4, and start kindergarten at 5. The exact year depends on your child's birthday and your state's cutoff date.
What age is pre-K?
Pre-K is for 4-year-olds. A child is usually eligible for pre-K in the fall of the year they turn 4 before the state's kindergarten cutoff date, which is September 1 in most states.
What is the average age for kindergarten?
Children start kindergarten at 5 in most of the United States. Depending on birthday and state cutoff, a child is between 4 years 8 months and 6 years old on the first day, and the average is a little over 5 and a half.
Can my child start kindergarten at 4?
Only where the cutoff is late. New York City uses December 31 and Vermont allows January 1, so a child born in the fall can start at 4 and turn 5 during the school year. A few other states let districts admit a younger child after an assessment. Most do not.
Should I hold my summer-birthday child back a year?
You can, and many families do. Children who start older tend to have an early edge that fades by the middle grades, so it is a judgment call about your child's readiness rather than a rule. Your preschool teacher's view is usually the best guide.
Does the calculator work outside the United States?
The state cutoffs are for the US. If you pick "Not sure or other" it uses September 1, which is also a reasonable guide for Canada, but other countries use different ages and terms, so treat the result as a rough estimate.
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