AgeCalc
Built for assessment work

Chronological age in years;months.days

The format record forms actually ask for — 10;11.17, not “about 11 years”. Plus corrected age for children born preterm, nearest-month rounding where an instrument requires it, and the published age range for 43 assessments. Nothing you type leaves your browser.

For Educators & Clinicians

By Assessment

All 43 instruments

Each page pre-selects the age format that instrument records, checks the age against the publisher's published range, and says whether corrected age applies.

Everyday Answers

Everyday & Novelty Calculators

Report-ready output

One click copies the bare years;months.days string — the thing that actually goes into the report, not a paragraph you have to edit.

Dates never leave your browser

Every calculation runs locally. No date of birth is transmitted, logged or stored — which matters when the date belongs to a student on your caseload.

Documented arithmetic

Month-end clamping, leap days and the 15-day rounding threshold are all written down in the methodology and covered by an automated test suite.