School Age Calculator

By the Age-Finder team · Last updated 7 November 2026

The School Age Calculator works out when a child can start school, using the rule your school system applies: the age a child must reach and the date they must reach it by.

It shows the earliest start, the child’s age on the cut-off date and on the first day, and whether they will be among the youngest or oldest in the class.

How to Use the School Age Calculator

Enter the child’s date of birth. Set the cut-off date: the date by which the child must reach the starting age. Enter the minimum starting age, for example 5. Choose the month the school year starts.

Select Calculate to see the earliest school start, with the child’s age on the cut-off date and on the first day. The defaults are a 1 September cut-off, a starting age of 5 and a school year that starts in September, and the starting age can be set from 2 to 8.

A date of birth in the future is rejected. Rules are set by countries, states, school districts and individual schools, so always confirm the date with the school or admissions office.

How the Rule Works

Most school systems use a cut-off date: a child can start in a given school year if they have reached the minimum age on or before the cut-off date of that year. A birthday on the cut-off day itself counts.

For example, with a rule of “5 years old by 1 September” and a school year starting in September: A child born on 31 August 2020 turns 5 on 31 August 2025 and can start in September 2025.

A child born on 2 September 2020 turns 5 two days after the cut-off and starts in September 2026. Two days of difference in birth date mean a whole year of difference in starting school. To check an age on a specific date yourself, use the Age on a Specific Date calculator.

Examples of Common Rules

In England, children usually start Reception in the September after their fourth birthday, and school becomes compulsory from the term after they turn five.

In the United States, kindergarten cut-off dates are set by each state, and some leave the decision to school districts. These examples show how rules are commonly written; check the current rule where the child will attend.

The cut-off dates in the United States run from 31 July to 1 January.

The Education Commission of the States publishes the current comparison for all 50 states and Washington, D.C., and its 2026 comparison shows 1 September as the most common cutoff, used in 22 of the 51 jurisdictions. The groups below are taken from that comparison:

Two details in the table are easy to misread. Michigan’s 1 December date is a parent-waiver date, not the statutory cut-off, which is 1 September.

And Connecticut moved from 1 January to 1 September in fall 2024, so older lists that still show 1 January are out of date. Cut-off dates are set by law and change, so confirm with the district before an enrolment decision.

The Grade Timeline

Once the start year is known, the rest of the school career follows one grade a year. The table below assumes a 1 September cut-off and a school year that starts in September.

A child who starts kindergarten in September 2025 is in 1st grade in September 2026, and so on, graduating in spring 2038 as the Class of 2038, thirteen school years after kindergarten began.

Worked through for the child in the example above: born 31 August 2020, kindergarten in September 2025 at age 5, 1st grade in September 2026, 12th grade in September 2037 at age 17, and graduation in spring 2038.

The child born two days later, on 2 September 2020, starts a year later and graduates in spring 2039. The UK has one more year than the U.S. system, Reception plus Years 1 to 13, so the last U.S. grade, 12th, lines up with Year 13.

Youngest and Oldest in the Class

A child born just before the cut-off date is among the youngest in their class, while a child born just after it is among the oldest, almost a year older than classmates born at the other end of the year.

The calculator shows the place in the class year as Youngest quarter, Oldest quarter or Middle.

For the two children in the example: the child born 31 August 2020 is 5 years, 0 months and 1 day old on 1 September 2025, the youngest in the class; the child born 2 September 2020 is 5 years, 11 months and 30 days old on 1 September 2026, the oldest in the class.

Some families of children born close to the cut-off consider starting a year later, sometimes called redshirting, or ask about early entry. Policies on both vary, so ask the school what is allowed.

The Cut-Off and the School Year

The cut-off date and the start of the school year are often different:

• For example, a U.S. district uses 1 September as the cut-off and starts school in mid-August.
• England uses 31 August as the cut-off and starts the school year in September.

The calculator uses the cut-off to decide eligibility, then shows the start of the school year that the cut-off falls in. A cut-off in the last month before a new school year, such as England’s 31 August, counts towards the year that starts next.

For our detailed guide to how cut-off dates are applied, read How to Calculate a Child’s Age on a Cutoff Date and School Enrollment Age: Cutoff Dates Explained.

Planning Ahead

If you are planning for a baby who is not yet born, or for a family move, you can try several dates of birth and rules to see how the start year changes.

Some parents also check what age their child will be when finishing school: add the number of school years to the start year, and use the Age on a Specific Date calculator to find the exact age on the last day.

Starting Age Around the World

Formal schooling begins at different ages. Many countries start primary school at 6, including much of Europe and South Asia, while the United Kingdom, Ireland, Australia and New Zealand start earlier, and some Nordic countries start at 7.

Preschool, kindergarten and reception years often come before the first compulsory year, so the “starting age” depends on which year you mean.

Enter the age that matches the year your child is applying for. Within the United Kingdom the rules differ by nation: England and Wales start Reception in the September after the fourth birthday, with a 31 August cut-off;

Scotland starts Primary 1 in August after the child turns 4, with a 28 February cut-off; Northern Ireland starts Primary 1 after the child turns 4, with a 1 July cut-off.

What other school age calculators offer

Most school age calculators on the first page give the same earliest start this one does. What sets them apart is the extra detail: state cut-off data, a grade timeline and a graduation year. The comparison below is against the three school age calculators that rank highest.

The gaps, stated plainly: the tool has no state cut-off data built in, so you enter the rule by hand; it shows no grade timeline and no graduation year; and it has no preset rules for a state or country.

What it adds is the place in the class year, which none of the three shows, and the state groups, the grade timeline and the graduation year worked through by hand in the guide.

Frequently Asked Questions

Sources

• GOV.UK: School admissions, when your child can start school (the rule in England).
• Education Commission of the States, Kindergarten Entrance Cutoffs, State K-3 Policies 2026 (the U.S. state cut-off dates in Table 2).
• Age-Finder methodology (how ages and 29 February birthdays are calculated).