Find someone’s precise chronological age in seconds, minutes, hours, days, months and years, for any test date or future event. Our tool returns clinician-grade results (rounded or exact), supports optional time of birth, and gives total months/weeks/days so you can use the numbers directly in reports, forms, and documentation.

How it works

1. Enter the person’s date of birth (month, day, year).
2. (Optional) Enter time of birth (hour, minute, second and AM/PM) if you require hour-level precision.
3. Enter the date you want the age calculated for (e.g., test date, evaluation date, or future date).
4. Click Calculate results appear instantly: full age (years/months/days), time remainder (hours/minutes/seconds), and cumulative totals (months, weeks, days, hours, minutes, seconds).

Example outputs

• Clinical screening: Child born 2018-09-14, assessed on 2025-03-10 → calculator returns exact 6 years, 5 months, 24 days plus totals; clinicians often use the rounded months to pick the correct age-band in screening tools.

Who benefits most

• Clinicians & therapists: Quick, precise age totals to include in assessment reports and to determine age-based norms.
• Parents & caregivers: Find exact age on milestones, appointments, and vaccinations.
• Teachers & administrators: Confirm eligibility dates for programs or determine grade placement cutoffs.
• Curious minds: See your age down to seconds, for fun or record-keeping.

FAQ

Q1. Does the calculator account for leap years?

A: Yes, it uses calendar date arithmetic so leap days and varying month lengths are handled correctly.

Q2. Can I calculate age on a future date (for planning)?

A: Absolutely. Enter the future date as the “age on” date to see what someone’s exact age will be on that day.

Q3. Why are total months and weeks useful?

A: Total months are commonly used by clinicians when selecting age-banded assessment sheets; total weeks/days are often needed in neonatal or infant care documentation.

Q4. Is time zone considered?

A: The calculator interprets the times you enter in your local browser timezone. For legal or cross-timezone cases, align both dates/times to the same zone before calculating to avoid discrepancies.

Accuracy

• The tool uses calendar math that accounts for leap years and month length differences the same approach used by leading online calculators. If you need rounded chronological age (for certain screening instruments), round to the nearest month as required by the instrument’s instructions.

Privacy

• Your inputs are processed locally in your browser: nothing is sent to third-party servers. Use the copy option to export a result; no personal data is stored by default.

Sources

Calculator.net, TheCalculatorSite, Brigance (Curriculum Associates), GigaCalculator, and Evalubox.