Calculate exact age from a birth date with optional as-of date. Fully client-side — no account, uploads, or remote storage.
Added Apr 18, 2026 · Updated May 1, 2026
Input
Result
Enter a value for date of birth to see your result.
Calculates exact age from a date of birth to today (or any other reference date), showing years, months, days, total days, and time until the next birthday.
From January 15, 1990 to April 18, 2026 is exactly 36 years and 3 months.
Inputs
Result
Age is calculated by counting full years since the birthdate, then full months in the remaining period, then remaining days. The 'as of' date defaults to today.
Yes — use the 'Age as of' field to specify any reference date instead of today.
Legal and cultural rules differ by country. Software typically treats Feb 29 as existing only in leap years and may roll to Feb 28 or Mar 1 in non-leap reference years — always confirm statutory age rules for compliance use cases.
For whole calendar days, use consistent local dates for birth and reference. Instant-based age across zones needs an explicit timezone; this tool assumes the dates you enter are already aligned to your intent.
No. Clinical gestational age and legal age cutoffs can depend on time-of-day, jurisdiction, and clock rules. Use this for general life-stage math only.