Age Calculator
Work out an exact age in years, months and days, at any date.
The date stays in this page. It is never sent anywhere and never stored.
Working out an age sounds like subtraction until you try it. Subtracting the years alone is wrong whenever the birthday has not come round yet this year, and dividing the days by 365.25 gives an answer that is close but never quite matches what anyone would say out loud.
More about Age Calculator
What people actually mean by an age is a calendar breakdown: whole years first, then whole months from what is left, then the days. That is what this tool reports, along with the total days lived, the total weeks, and how long until the next birthday. The order matters, because taking the units in a different sequence gives a different and less useful answer.
Two conventions are worth stating plainly, since both are choices rather than facts. A 29 February birthday is treated as falling on 28 February in a common year, so somebody born on a leap day turns a year older on the 28th rather than waiting until 1 March. And months are clamped to the end of the target month, so a period that starts on the 31st and ends in a short month does not silently roll forward.
The second field lets you ask the question in the other direction: how old will I be on a given date, or how old was I at some point in the past. Leave it empty and it uses today.
- Years, months and days, taken in that order rather than approximated
- Total days and weeks lived, for the counts people actually want
- Next birthday with a countdown, or a note when it is today
- Age at any date, past or future, not only at this moment
- Leap-day birthdays handled with a stated convention rather than silently
- Refuses a date of birth in the future instead of showing a negative age
How to use it
- 1Enter the date of birth.
- 2Read the age in years, months and days as it appears.
- 3Leave the second field empty for today, or set it to ask about another date.
- 4Copy the breakdown with the copy button if you need it elsewhere.
Questions
How is the age calculated?
Whole years first, then whole months from the remainder, then the days left over. That is the order that matches how people say an age out loud.
What happens with a 29 February birthday?
In a common year the birthday is treated as 28 February, so the age increases on the 28th. In a leap year it falls on the 29th as normal.
Why does the day count differ from years times 365?
Because leap years add a day roughly every fourth year. The total is counted on the calendar rather than multiplied out, so it is exact.
Can I work out my age on a future date?
Yes. Put the future date in the second field and it will tell you how old you will be then.
Is my date of birth stored anywhere?
No. The calculation happens in the page and the date is gone when you close the tab.