This calculator determines exact age or time spans between two dates, presenting results in years, months, weeks, days, hours, minutes, and seconds.

Age Calculator

Date of Birth:

Age at the Date of:

Result

Age Calculation Note:

This calculator uses the international standard age system where:

• Age increments on each birthday

• Partial years are not rounded up (e.g., 3 years and 11 months = age 3)

• Most Western countries follow this convention

Cultural Variations:

1. East Asian Systems:

- Traditional Chinese: Babies start at age 1

- Age increases at Lunar New Year, not birthdays

- Example: A baby born before Lunar New Year becomes age 2 days later

2. Year-Counting Differences:

- Some cultures count current year (e.g., "21st year of life" = age 20)

3. Month Calculation Notes:

- Standard calculation: Feb 20 → Mar 20 = 1 month

- End-of-month special cases:

    Method A: Feb 28 → Mar 28 = 1 month + 3 days (our approach)

    Method B: Feb 28 → Mar 31 = 1 month (both treated as month-ends)

- Similar ambiguities occur for:

    April 30 → May 31
    May 30 → June 30
- These arise from varying month lengths