About ChronoCalc

How ChronoCalc Started

ChronoCalc did not begin as a startup pitch. It started in shared clinic group chats — the kind where someone asks "does anyone have a working link to the Pearson age calculator?" and gets three broken bookmarks back.

We are a collective of practicing clinicians: SLPs scoring CELF-5 batteries, school psychologists running WISC-V evaluations, OTs documenting developmental milestones, and NICU follow-up staff tracking corrected age for preterm infants. Different specialties, same frustration — accurate test-age calculation should not depend on a publisher maintaining a free web page.

When Pearson publicly confirmed they no longer host a live age calculator, the gap became urgent. Generic birthday calculators do not apply Wechsler rounding rules. Spreadsheet formulas break on leap years. Manual borrowing errors happen at the worst possible moment — right before a due evaluation report.

So we built what we wished existed: a calculator that understands Y;M;D for CELF-5, Y;M with rounding for WISC-V, exact age for BRIGANCE, and corrected age for preemies — with copy-ready output and zero data upload.

Why the Pearson Shutdown Matters

For more than a decade, Pearson's free age calculator was the default tool in schools, private practices, and hospital outpatient clinics. It was bookmarked on every evaluator's browser, linked from district intranet pages, and referenced in graduate training programs.

Its removal did not change how assessments work. WISC-V still requires Y;M with nearest-month rounding. CELF-5 still requires Y;M;D to the testing date. What changed is that clinicians need an independent, reliable alternative — one that will not disappear when a publisher reorganizes their website.

ChronoCalc fills that role. We are not affiliated with Pearson or any assessment publisher. We built the tool to match manual conventions so clinicians can keep working without interruption. See our Pearson alternative guide for migration steps.

What We Built and Why

Every feature on ChronoCalc exists because a clinician asked for it:

• Assessment-specific formatting — Y;M;D for SLP tools, Y;M with rounding for Wechsler protocols, exact age for BRIGANCE
• Clinical mode toggle — Switch between exact age and publisher-aligned rounding without a separate tool
• Copy and print — One-click export formatted for score sheets and evaluation reports
• Corrected age calculators — For NICU follow-up and early intervention workflows
• Local-only processing — Dates never leave the browser (see our privacy policy)

We validate calculation logic against administration manual conventions and update when publishers release new editions or scoring guidance changes.

Our Privacy Promise

Clinical calculators handle sensitive information — dates of birth, testing dates, gestational ages. We designed ChronoCalc so that none of that data touches our servers.

All age calculations run in your browser using JavaScript. We do not collect dates of birth, store calculation results, or use analytics pixels that track individual sessions. No registration, no accounts, no usage caps. Your workflow stays yours.

We believe privacy is a clinical requirement, not a marketing feature. Read the full details on our privacy policy page.

Free, Always

ChronoCalc will remain free for personal, educational, and clinical use. Accurate age calculation should never be paywalled behind a subscription or locked inside publisher software. Evaluators, students, and parents all deserve access to the same reliable tools.

Join Us as a Co-Author

We write clinical guides — corrected age, assessment formatting, Pearson migration — from a practitioner perspective. If you are a credentialed SLP, school psychologist, OT, neonatologist, or developmental pediatrician interested in co-authoring educational content, we want to hear from you.

We do not invent fake credentials or fabricated institutional affiliations. Real clinical voices make our content trustworthy. Reach out through our contact page with your credentials, specialty area, and topic ideas.

Get in Touch

Questions, bug reports, feature requests, or partnership inquiries — we read everything. Contact us through the contact page or email support@chronocalc.org. We typically respond within one business day.

ChronoCalc is an independent tool. Assessment names referenced on this site are used for descriptive purposes only and do not imply endorsement by any publisher.