Age Calculator
Find your exact age in years, months and days, plus total days lived and your next birthday countdown.
Assumptions used in this calculation
- Calendar: Uses the Gregorian calendar and the user's local time zone for "today".
About this calculator
Working out someone's exact age in years, months and days, not just years, means carefully accounting for how many days are in each month between two dates, including leap years, which is fiddly enough that it's easy to get off by a day doing it by hand. This calculator takes a date of birth and an optional comparison date and returns a full breakdown: complete years, months and days elapsed, plus total months, total weeks and total days lived, the day of the week you were born on, and a countdown to the next birthday. It's useful for anything from filling out an official form that asks for exact age, settling a friendly argument about who's older by how much, or just satisfying curiosity about a birth date's day of the week. Because it also accepts a custom comparison date rather than only 'today', it works equally well for calculating someone's age as of a specific past or future event, not just their current age.
Worked example
Age of someone born 15 Aug 1990, measured today
Result: 35 years, 10 months, 29 days (as of 2026-07-14)
How to use this
- 1Enter your date of birth.
- 2Optionally set a different "as of" date instead of today.
- 3Read your exact age in years, months and days.
Troubleshooting
The result looks wrong by a day.
Age calculations depend on your browser's local timezone, if you're near midnight the date can shift by one day.
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