Age Calculator
Find exact age in years, months, and days from a birth date.
The age appears here
Enter a date of birth to see the exact age in years, months, and days, the total days lived, and the countdown to the next birthday — all computed in your browser.
Runs entirely in your browserCalculate an exact age, locally
Pick a date of birth and, optionally, a date to measure to (it defaults to today). The tool works out the exact age in years, months, and days, handling different month lengths and leap years correctly. It also shows the total days lived and the countdown to the next birthday. Everything is computed in your browser — the dates you enter are never uploaded.
Common questions
How is the exact age calculated?
The tool subtracts the birth date from the target date calendar-aware: it counts whole years, then whole months, then the remaining days, borrowing from the previous month's real length when the day-of-month would go negative. This matches how people naturally state an age.
Does it handle leap years?
Yes. Because the calculation walks real calendar months and days rather than assuming a fixed 30 or 365, February 29 and leap years are counted correctly.
Can I calculate age at a past or future date?
Yes. Leave the second date blank to use today, or set it to any date to find the age at that point — for example someone's age on a specific anniversary.
What does 'days until next birthday' mean?
It counts the days from the target date to the next occurrence of the birth month and day. On the birthday itself it reads zero.
Are my dates uploaded anywhere?
No. The calculation runs entirely in your browser with JavaScript. The dates you enter are never sent to a server or stored anywhere.