How your age is calculated
Your age is the time between your date of birth and today. The calculator first counts the full years and months since you were born, then counts the days left over. If your birth date falls on a day the current month doesn’t have, such as the 31st, it uses that month’s last day.
Age = full years + full months + remaining days since your date of birth
How to use this calculator
- Enter your date of birth. Use the day, month and year you were born.
- Check the second date. It starts at today. Change it to find your age on any other date.
- Read your result. Your age, total days lived and next birthday update instantly.
Worked example
Someone born on June 15, 1990 has had 35 birthdays by March 2, 2026. Their last birthday was June 15, 2025. Eight full months later is February 15, 2026, and March 2 is 15 days after that. Their age is 35 years, 8 months and 15 days, which is 13,044 days in total.
What your result shows
| Result | What it means |
|---|---|
| Years, months, days | Your exact age on the chosen date |
| Total months | Every full month since you were born |
| Total weeks and days | All the days you have lived, in weeks |
| Next birthday | The date and day of the week it falls on |
Birthdays on February 29
If you were born on February 29, this calculator treats February 28 as your birthday in years that aren’t leap years. Rules for legal purposes vary by country and state, so check what applies to you if the exact date matters.
Frequently asked questions
How do I calculate my exact age?
Count the full years since your date of birth, then the full months since your last birthday, then the days left over. This calculator does all of that for you.
Can I find my age on a past or future date?
Yes. Change the “Age on this date” field to any date after your date of birth.
How is age calculated for someone born on February 29?
This calculator uses February 28 as the birthday in years that aren’t leap years. Legal rules vary by location, so check locally if the exact date matters.
Was this tool helpful?
Thanks for your feedback.