School age guides
Guides for parents navigating kindergarten enrollment, grade level questions, cutoff dates, and school system comparisons — written from the perspective of what parents actually need to know, not what a textbook would say.
A full reference table for ages 4–18, why the same age can mean two different grades, and how to handle borderline birthdays.
How cutoff dates work, why states use different ones, what "on or before" means, and what to do if your child just misses the deadline.
When early entry is possible, how readiness assessments work, what research says about starting early vs. waiting, and how to request an evaluation.
The K–12 structure explained: grade stages, school year naming, the freshman/sophomore/junior/senior system, and what determines grade placement.
Starting ages, cutoff rules, and grade structures for 15+ countries including the UK, Canada, Australia, Japan, Finland, and more.
The enrollment deadline for all 50 US states — verified against state education codes.
Typical age ranges for every grade from Pre-K through Grade 12, with notes on when elementary, middle, and high school begin.
Use the calculator
Every guide on this site links back to the free school age calculator, which gives you a precise answer for any birthday in any US state, Canadian province, Australian state, or UK region. Select your country, pick your region, choose your child's birth date, and you get their current grade, the school year they start kindergarten, their age on that first day, and a full K–12 timeline through graduation.