Resource Library
Field-tested resources for SLPs, school psychologists, and clinicians who need precise age calculations for assessments, eligibility reviews, and documentation.
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Biological age estimates how your body has aged. Chronological age records how long you have lived. In every formal assessment, eligibility review, and legal record, only one of them belongs.
A basic 'how old am I' tool and a professional chronological age calculator produce similar-looking outputs, but they are built for different purposes. Here is what to look for.
From the basic year-month-day subtraction to February 29 edge cases and premature infant corrected age — everything you need to calculate chronological age accurately by hand.
Subtracting two birth years gives you a rough answer. Getting the exact age gap in years, months, and days requires a few extra steps — here is how to do it correctly.
Counting down to your birthday sounds simple — but getting the exact number of days requires checking whether your birthday has already passed this year, and whether a leap year is involved.
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Browser-based, private, no sign-up. Enter two dates and get years · months · days instantly.
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