Age Calculator
Calculate your exact age in years, months and days from your date of birth.
How to Use the Age Calculator
Enter your date of birth and click Calculate. The calculator will show your exact age in years, months and days along with additional details like total months, weeks, days and hours lived. You can also calculate your age on a specific date by filling in the optional field.
How Age Is Calculated
Age is calculated by finding the difference between your date of birth and the current date (or a selected date). The calculator accounts for varying month lengths and leap years to give you an accurate result.
Age Calculation Formula
The formula compares years, months and days separately:
- If the current day is less than the birth day, borrow days from the previous month.
- If the current month is less than the birth month, borrow 12 months from the year.
- Total days = difference in milliseconds ÷ (1000 × 60 × 60 × 24)
Example Calculation
If your date of birth is 15 January 2000 and today is 29 August 2026:
- Age: 26 years, 7 months, 14 days
- Total months: 319
- Total weeks: 1,389
- Total days: 9,722
Frequently Asked Questions
How old am I today?
Enter your date of birth in the calculator above and click Calculate. It will instantly show your exact age in years, months and days as of today.
How do I calculate age from date of birth?
Subtract your birth date from today's date. The calculator handles month lengths and leap years automatically to give you an exact result in years, months and days.
How is age calculated?
Age is calculated by computing the difference between two dates — your birth date and the current date. Days are adjusted for varying month lengths, and months are adjusted when the birth month hasn't occurred yet in the current year.
How many days old am I?
The calculator shows your total age in days. For example, someone born on 1 January 2000 would be approximately 9,737 days old on 29 August 2026.
Can I calculate my age on a future or past date?
Yes. Use the optional "Calculate Age On" field to enter any date. The calculator will show your age as of that specific date instead of today.