Age Calculator
Get an exact age in years, months, and days between any two dates.
Enter your dates
The birth date must be on or before the "as of" date.
Your results
Age
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How it works
The calculator counts full calendar years first, then full months, then the leftover days:
- Years = difference in year numbers, minus one if this year's birthday hasn't happened yet.
- Months = remaining month difference after years are removed.
- Days = remaining day difference; if negative, a month is borrowed and days are counted from the real length of the previous month.
Because it walks the actual calendar, leap years and months of different lengths are handled automatically. Total days is the straight day count between the two dates.
Frequently asked questions
How is exact age in months and days calculated?
Full years are counted first, then full months, then the remaining days. When the day of the month has not been reached yet, a month is borrowed and days are counted using the actual length of the previous month, so leap years and varying month lengths are handled correctly.
Do leap years affect the result?
Yes, and they are handled automatically. Because the calculation walks the real calendar — borrowing days from the actual previous month — February 29 and leap years are accounted for without any special input.
Why do online age calculators sometimes disagree by a day?
Differences usually come from time zones or from whether the end date is counted inclusively. This calculator uses plain calendar dates with no time-of-day, so two dates always give the same answer.
Can I calculate age as of a past or future date?
Yes. Change the "as of" date to any date after the birth date — for example, to find how old someone was on a wedding day or will be on a future birthday.