What is the School Starting Age Calculator?
This calculator determines how old a child will be on a school's enrollment cutoff date and whether they meet the minimum age required to start school. Cutoff dates and required ages vary by country, state, and district — common cutoffs include September 1, August 1, or December 31, and typical required ages are 4, 5, or 6 years. Enter your own values to match your local rules.
How to use it
Enter the child's date of birth, the school's cutoff date, and the minimum age (in years) the child must reach by that cutoff. The tool reports the child's exact age in years, months, and days on the cutoff date, the age as a decimal, and a likely-eligible verdict.
The formula
Age on cutoff = cutoff date − birth date. The decimal age is computed as total days divided by 365.25 (accounting for leap years). The child is considered eligible when this decimal age is greater than or equal to the required years.
$$\text{Age}_{\text{years}} = \frac{\text{Cutoff Date} - \text{Birth Date}}{365.25} \geq \text{Required Years} \;\Rightarrow\; \text{Eligible}$$
Worked example
A child born September 15, 2020 with a cutoff of September 1, 2025 and a 5-year requirement: from Sep 15 2020 to Sep 1 2025 is 4 years, 11 months, and 17 days — a decimal age of about \(4.96\) years. Since \(4.96 < 5\), the child is not yet eligible and would typically wait for the next intake.
FAQ
Why 365.25 days per year? It averages in leap years so the decimal age is accurate over multi-year spans.
Is this legal advice? No. Cutoff dates and age rules differ by jurisdiction and can include exemptions or early-entry assessments. Always confirm with your local school authority.
What required age should I use? Use whatever your district specifies on its cutoff date — commonly 5 years for kindergarten in the US, or your local equivalent.
