Age Calculator
Calculate exact age in years, months, and days from a birth date, plus total days and weeks lived.
About the Age Calculator
Age is more than a single number of years — this calculator gives you exact years, months, and days between a birth date and any reference date, plus the total number of days and weeks lived, useful for legal forms, milestone tracking, or simple curiosity.
How It Works
The calculator compares the birth date to the reference date (today, by default), first finding the difference in years, then adjusting for months and days by borrowing from the previous month or year whenever the day-of-month or month component would otherwise be negative — the same logic used for calendar-accurate date subtraction. It separately counts total elapsed days to compute total weeks lived.
Age = (Years, Months, Days) between Birth Date and Reference Date, adjusted so each component stays non-negative using calendar month lengths.
Example
Scenario: Someone born on June 15, 1990, measured as of today.
Result: An exact age expressed as years, months, and days, along with total days and weeks lived since birth.
Assumptions & Limitations
- Uses calendar months and years, so month lengths vary (28-31 days) exactly as they do on a real calendar, including leap years.
- Defaults the reference date to today if no 'as of' date is provided.
- Does not account for time zones — the calculation uses calendar dates only, not exact time-of-day.