Age Calculator
Calculate exact age in years, months, days, hours and minutes.
About Age Calculator
Age looks trivial until you need it precisely: months have different lengths, leap years shift the count, and "two years and eleven months" is not the same as "35 months" in every context.
This calculator gives the exact elapsed time between a birth date and any reference date, broken into years, months and days, plus the total in each unit and a countdown to the next birthday.
How Age Calculator works in your browser
Age is calculated by calendar arithmetic rather than by dividing elapsed days by 365.25. Years are counted first, then months, then the remaining days — which is how age is defined legally and conventionally, and it is why the answer changes on your birthday rather than gradually.
Leap years are handled by the date arithmetic itself, so someone born on 29 February gets a correct age in every year; the anniversary is treated as 1 March in common years, which is the convention most jurisdictions use.
All arithmetic runs in your device’s local time zone. If you were born in a different zone from the one you are in now, the day boundary may differ by one from what you expect.
When to use it
- Confirming an exact age in years, months and days for a form or an application.
- Checking eligibility against an age threshold on a specific future date.
- Working out the precise gap between two people’s birthdays.
- Calculating an age from a date of birth without entering it into a site that stores it.
Frequently asked questions
How do I work out my exact age?
Enter your date of birth. The result is counted in calendar years, months and days rather than by dividing total days, which is how age is defined legally.
How are leap years handled?
Calendar arithmetic is used rather than a fixed 365-day year, so leap days are counted correctly.
What happens on 29 February birthdays?
In non-leap years the anniversary is treated as 1 March, which is the most common civil convention.
Can I calculate age at a past or future date?
Yes, change the "as of" date to any date you like.