Age Calculator

To use this age calculator:

1. Enter your birth year, birth month, and birth day.
2. Optionally adjust the target date fields (year, month, day) if you want to calculate your age on a specific date other than today.
3. The calculator instantly displays your age in years, months, and days, as well as total days and weeks lived.

All fields update the results in real time as you change them.

An age calculator determines your exact age based on your date of birth and a target date. Rather than simply subtracting birth year from the current year, it computes the precise difference in years, months, and days, accounting for varying month lengths and leap years.

This tool also provides total days and weeks lived, giving you a comprehensive picture of the time elapsed since your birth.

The age calculation involves these steps:

• Years: Target Year − Birth Year, adjusted down by 1 if the birthday has not yet occurred in the target year.
• Months: Target Month − Birth Month, adjusted by adding 12 and subtracting a year if negative.
• Days: Target Day − Birth Day, adjusted by adding the number of days in the previous month if negative.
• Total Days: Exact difference in milliseconds between the two dates, divided by 86,400,000 (the number of milliseconds in a day).
• Total Weeks: Total Days divided by 7, rounded down.

Example 1: Born on March 15, 1990, target date February 12, 2026. Age: 35 years, 10 months, 28 days. Total days: approximately 13,083.

Example 2: Born on December 31, 2000, target date January 1, 2026. Age: 25 years, 0 months, 1 day.

Example 3: Born on February 29, 2000 (leap day), target date February 28, 2025. Age: 24 years, 11 months, 30 days.