Age Calculator
Enter a birth date to calculate exact age in years, months, and days.
Enter a birth date and get an exact age breakdown - years, months, and days, along with total days lived and a countdown to the next birthday. Everything runs with plain JavaScript in your browser, so the date you enter never leaves your device.
How to use it
- Pick a birth date in the first field.
- Leave "Calculate age as of" set to today, or change it to see the age on any other date.
- Click "Calculate Age" to see the full breakdown.
Frequently asked questions
Is my birth date sent to a server?
No - every date you enter stays in your browser. The age is calculated with plain JavaScript, nothing is uploaded anywhere.
Can I calculate my age as of a date other than today?
Yes - change the "Calculate age as of" field to any date, past or future, and the breakdown updates for that date instead of today.
How is the years/months/days breakdown calculated?
It counts whole calendar years and months first, then whatever days are left over - so "31 years, 2 months, 9 days" means 31 full years and 2 full months have passed since the birth date, plus 9 more days.
Why does the day count look different from just subtracting the dates?
Calendar months have different lengths, so the tool walks month by month from the birth date instead of dividing total days by 30 - that keeps the years/months/days figures accurate instead of approximate.