Age Calculator
The Age Calculator computes your exact age in years, months, and days from your birth date, plus your total days lived and days until your next birthday.
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How This Tool Works
Enter your birth date (and optionally a different comparison date) to see your exact age, total days lived, and days until your next birthday.
Formula & Method
We calculate the calendar difference between your birth date and today (or a chosen date), correctly handling varying month lengths and leap years.
Example Calculation
Someone born on March 15, 1990 turns 36 on March 15, 2026 — as of earlier in 2026, the calculator would show their age as 35 years and some months.
Frequently Asked Questions
How is age calculated with leap years?+
The calculator uses actual calendar dates, so leap years are automatically handled correctly without any special adjustment needed.
Can I calculate someone's age on a future or past date?+
Yes, use the optional "calculate age as of" field to see what someone's age was, or will be, on any specific date.
Why does my age in months not match a simple calculation?+
Because months have different lengths (28–31 days), the calculator counts complete calendar months rather than assuming a fixed 30-day month.
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