How to use the age calculator
Enter a date of birth. The second box starts on today's date. Change it to find how old someone was, or will be, on any other day, which is handy for school entry cut-offs, visa forms and retirement dates.
The formula
The calculator counts whole years from the date of birth, then whole months since the last birthday, then the days left over. Leap years are handled exactly. Someone born on 29 February is counted as having their birthday on 28 February in years without a leap day.
Worked example
Someone born on 15 June 1995 is, on 10 October 2026, 31 years, 3 months and 25 days old: 31 whole years to 15 June 2026, three more months to 15 September, and 25 days after that.
Common questions
Does it count the day I was born?
No. Like most official age calculations, it counts the days that have passed since your date of birth.
Why do some countries count age differently?
In the traditional East Asian system a baby is one at birth and everyone gains a year at new year. This calculator uses the international system.
How many days old am I?
The "In days" row shows the exact count, including every leap day you have lived through.