Fact-Checking Policy
Because parents use this site to make real enrollment decisions, factual accuracy matters more here than on a typical content site. This page describes how we verify the rules, dates, and statistics we publish.
Primary sources first
Kindergarten cutoff dates, compulsory-attendance ages, and program eligibility rules are checked against primary sources: state education codes (for example California Education Code §48000, Ohio Revised Code 3321.01, Washington RCW 28A.225.160), official state education-department publications, and district enrollment policies. Secondary summaries are used only to orient research, never as the sole basis for a published rule.
Handling uncertainty
Some states set no uniform cutoff and delegate the date to individual districts (Massachusetts, New Hampshire, Pennsylvania, Vermont). In these cases we do not invent a single number — we label the state "varies by district" and instruct readers to confirm locally. Where legislation is newly signed but not yet in effect, we label it with its effective date.
Statistics and research claims
When we cite research — for example on the relative age effect, redshirting outcomes, or Transitional Kindergarten results — we attribute the finding to its source body of work and avoid overstating causation. Mixed or contested research (such as the long-term effects of academic redshirting) is presented as mixed, not as a verdict.
The calculator itself
The calculation logic is deterministic and documented publicly in the methodology, including edge cases such as February 29 birthdays and "on or before" cutoff comparisons. The same logic is covered by an automated test suite so that changes do not silently alter results.
Corrections
When we confirm an error, we correct the page promptly and record material corrections in the public changelog. To report a possible error, email hello@school-age-calculator.info with the page URL and, if possible, the official source. Reports that include a primary source are verified and actioned fastest.