How your age is calculated
Your age is the time from your date of birth to today. The calculator counts the number of full years, then the remaining months and days, handling different month lengths and leap years. It also shows the total number of days you've been alive.
A worked example: someone born on 15 March 1990, checked on 20 July 2026, is 36 years, 4 months and 5 days old. The calculator first counts the 36 complete years, then steps forward month by month to 15 July 2026, and finally counts the 5 remaining days. Because months are not all the same length, the leftover day figure depends on which months the gap crosses — that is why the same person can be "4 months and 5 days" past their birthday in one year and "4 months and 4 days" in another.
The age in days calculator answers the question that usually follows this one.
How to use this calculator
Pick your date of birth and the result updates instantly with your exact age and total days. To count between any two dates instead, use the days between dates calculator.
People usually want one of three numbers: age in whole years for forms and eligibility, the full years-months-days breakdown for milestones, or total days lived for curiosity and record-keeping. All three appear together, so you do not have to convert anything by hand. A rough sanity check on the total: one year is about 365.25 days, so 30 years is roughly 10,958 days.
Many people follow this up with the birth year calculator.
Frequently asked questions
- How do I calculate my exact age?
- Count the full years from your birth date to today, then the leftover months and days. This calculator does it automatically, including leap years.
- How many days old am I?
- It's the number of days from your birth date to today — the calculator shows this as 'days total'.
- Does it account for leap years?
- Yes. The day count is based on the actual calendar, so leap days are included.
- Why does the month/day part change near my birthday?
- Because age in years only increases on your birthday; the months and days fill in the time since your last birthday.
- What happens if I was born on 29 February?
- Your age still increases once a year. In non-leap years most systems treat 1 March (or 28 February in some countries) as the birthday, but the total day count shown here is unaffected because it uses the real calendar.