Enter an age to find the birth date. A whole year gives a born-between window; add months and days to pin an exact date.
Years is required. Months and days are optional and narrow the result.
Defaults to today. This is the date the age applies to.
Put in an age and a reference date, and this tool works backwards to the date of birth. If you give only a whole-year age, you get a born-between window, because lots of birth dates share the same age. Add months, and then days, and it narrows down to one exact date.
How to find a date of birth from an age
If all you know is that someone is, say, 45 years old, their birth date could fall anywhere across a one-year window. So the tool shows the earliest and latest possible birth date, along with the year or two years involved. Add the months and it narrows to about a month; add the days and it pins one date. And every single date it gives is double-checked by working the age forward again, so a month-end edge can never throw up a wrong date.
Frequently asked questions
How do I find a date of birth from an age?
Enter the age and a reference date. A whole-year age gives you the born-between window; add months and days to narrow it down to one exact birth date.
Why does an age in years give a range of dates?
Because everyone born within a one-year span has the same whole-year age. Adding months and days narrows the range until it lands on a single date.
What year was someone born if they are a certain age?
Enter the age on the reference date and the tool shows you the year, or the two possible years, along with the exact born-between window.