Age Calculator
Enter your date of birth to find out your exact age in years, months, and days — plus total months, weeks, and days lived.
Sample birth dates:
Calculated locally in your browser.
How to use
- Enter your date of birth — type or use the date picker.
- Set the “as of” date — defaults to today, but you can calculate your age on any date.
- The result shows your age in years, months, and days, plus totals in months, weeks, and days.
Example
- Date of birth: January 15, 2000
- As of: September 18, 2026
- Result: 26 years, 8 months, 3 days
How age is calculated
- Years — counted from birthday to birthday.
- Months — remaining months after full years.
- Days — remaining days after full months. Month lengths (including leap years) are accounted for exactly.
Leap year birthdays
If you were born on February 29, the calculator handles this correctly for any target year, including non-leap years.
Frequently Asked Questions
How does the calculator handle leap year birthdays (February 29)?
For individuals born on February 29 (leap day), the calculator precisely computes calendar years and considers the birthday as March 1 in common non-leap years, preserving exact elapsed day totals.
Does the calculator use my local timezone or server time?
The tool evaluates dates using your device's local system timezone, ensuring the 'today' reference matches your physical clock rather than a remote server.
Can I calculate my age on a future date?
Yes. You can change the 'As of' date field to any target date in the future (such as retirement, marriage, or anniversary) to determine your exact age on that date.
What is the difference between Western and traditional East Asian age?
Western age starts at 0 at birth and increases on birthdays. Traditional East Asian age counted 1 year at birth and incremented on New Year's Day. South Korea officially adopted the international standard in 2023, matching this calculator.
How are total days, weeks, and months calculated?
Total days represent the exact elapsed time accounting for all leap years (366-day years). Total weeks equal days divided by 7, and total months represent accumulated calendar months.
Is my date of birth stored or transmitted anywhere?
No. Date calculations execute 100% client-side in your browser runtime. Zero personal dates are saved, sent across networks, or tracked.