Everyday math & dates
Age Calculator
Enter a date of birth. The second date is set to today, but you can change it to find someone's age on any date.
Your result will appear here.
How it's calculated
Full years are counted first, then full months after the last birthday, then the days left over. If you were born on the 31st, a month later falls on the last day of a shorter month, the same rule Excel's EDATE uses.
Excel's DATEDIF counts the same way for most dates. Its "MD" option can return odd results near the end of a month, which is worth knowing if you check the answer in a spreadsheet.
How to do it in Excel
=DATEDIF(A2, TODAY(), "Y")- Age in full years, with the date of birth in A2.
=DATEDIF(A2,TODAY(),"Y")&" years, "&DATEDIF(A2,TODAY(),"YM")&" months, "&DATEDIF(A2,TODAY(),"MD")&" days"- Age in years, months and days as text.