How to use the age calculator
- Enter your date of birth in the first field.
- The result updates instantly — no button to press.
- Read your exact age in years, months and days, plus total days lived, the weekday you were born and a countdown to your next birthday.
- Optionally set the “Age at date” field to find how old you were (or will be) on any other day.
How age is calculated (the formula)
Your age is the time elapsed between your birth date and a reference date (today, by default). Because calendar months have different lengths, you can’t just divide days by 30. The calculator counts complete units in order:
months = whole months after those years
days = leftover days (borrow a month if needed)
When today’s day-of-month is earlier than your birth day-of-month, the calculator “borrows” the number of days in the previous month — exactly like long subtraction. This is the standard way human age is expressed and matches how you’d count it on a calendar. Leap days (29 February) are included automatically because real dates are counted.
Worked examples
Example 1 — born 15 June 1995, today 15 June 2026
From 1995 to 2026 is 31 complete years. The month and day match exactly, so the answer is 31 years, 0 months, 0 days — and it’s your birthday.
Example 2 — born 20 January 2000, today 5 January 2026
You haven’t reached January 20th yet, so you’re still 25, not 26. Counting back: 25 years, then from 20 Dec to 5 Jan is 11 months and 16 days → 25 years, 11 months, 16 days.
Frequently asked questions
Enter your date of birth and read the “days lived” figure. It counts every calendar day between your birth date and today, leap days included. People often search this to celebrate round numbers like 10,000 days old.
Subtracting years only works after your birthday has passed this year. Before your birthday you’re a year younger than that quick subtraction suggests. This calculator checks the month and day, so it’s always right.
Yes. Total days always include real leap days. For a 29 February birthday, in non-leap years your “birthday” for counting purposes rolls to 1 March, which is the most common convention.
The calculator shows your Western (tropical) zodiac sign based on your birth date — the same sign used in horoscopes.
No. The whole calculation happens in your browser. Nothing you type is sent to a server or saved. See our privacy policy for details.