Online Chronological Age Calculator

Report Date (MM/DD/YYYY):

Birth Date (MM/DD/YYYY):

Years:

Months:

Days:

Pearson Borrow-30 Method

This calculator uses the Pearson borrow-30 method — the same calculation standard required by major standardized assessments including the CELF, PLS, GFTA, PPVT, and Goldman-Fristoe. It produces the exact years-months-days result that test manuals demand.

Unlike a simple date subtraction, the borrow-30 method handles month-length variations correctly: when the report day is smaller than the birth day, the calculator borrows 30 days (one month). When the report month is smaller than the birth month, it borrows 12 months (one year). This matches the hand-calculation method described in standardized test administration guides.

How to Use

Report Date — the date of the evaluation or report. Defaults to today, but you can set it to any past date for backdated reports.
Birth Date — the child or client's date of birth.
Press Calculate Age or hit Enter to see the result.

Who It's For

Speech-Language Pathologists, school psychologists, occupational therapists, special education teachers, clinical psychologists, developmental pediatricians — anyone who administers standardized assessments and needs accurate chronological age.

Want It On Your Phone?

The Chronological Age Calculator app for iPhone and iPad has the same Pearson borrow-30 calculation, plus the ability to set any report date and get results instantly. Completely free, no ads.