⏳ Age Calculator
Calculate your exact age instantly as you type. Find your age in years, months, and days with optional hours and minutes. Discover your next birthday, upcoming milestones, compare ages, and explore fascinating birth date insights—all timezone-aware with bulletproof leap year logic.
📅Your Information
📅 10/17/2025 (Today)
🎂Your Age
Enter your date of birth above to see your exact age
👥Compare Ages (Optional)
Compare two birth dates to see the exact age difference in years, months, and days.
📖How It Works
▼Learn about age calculation rules and special cases
📖How It Works
▼📅February 29 Birthday Rule
If you're born on February 29 (a leap year), your birthday in non-leap years is observed as February 28 by default.
This is the most common convention for leap year birthdays. Your age still increments properly every year, and the next birthday countdown will show Feb 29 in leap years, Feb 28 otherwise.
🔢Month & Day Borrowing
Age calculation uses calendar arithmetic with borrowing, similar to subtraction with carrying.
Example 1:
Born: Jan 31, 2000 → Today: Mar 15, 2025
Result: 25 years, 1 month, 14 days (borrowing handles month-end correctly)
Example 2:
Born: Dec 25, 2000 → Today: Jan 10, 2025
Result: 24 years, 0 months, 16 days (borrows from year when month goes negative)
🌍Timezone & Daylight Saving
All calculations are performed in the selected timezone. If you include birth time and reference time, switching timezones can shift results by a day if the times cross midnight.
For most users, using your local timezone (browser default) without specifying times is the simplest and most accurate approach.
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❓Frequently Asked Questions
How do you calculate age exactly with months and days?▼
Age calculation uses calendar arithmetic. We count complete years from your birth date, then complete months in the current year, then remaining days. The algorithm properly handles month boundaries and leap years. For example, if you're born on January 31 and today is March 28, we calculate full years until the last January 31, then full months until the last day-of-month match, then remaining days.
How do leap years and Feb 29 birthdays work?▼
If you're born on February 29 (a leap year), your birthday in non-leap years is observed as February 28 by default. This is the most common convention. Our calculator handles leap year logic correctly, ensuring your age increments properly every year and your next birthday countdown shows the correct date (Feb 29 in leap years, Feb 28 otherwise).
How do I find my age on a specific date?▼
Simply enter your date of birth and then set the 'Reference Date' field to any date you want (past or future). The calculator will instantly show your age on that specific date. This is useful for finding out how old you were on a historical date or will be on a future date.
Why can timezone/daylight saving change results by a day?▼
Age calculations depend on the exact moment of time. If you include birth time and reference time, switching timezones can shift the calculation by hours, which might cross a day boundary. For example, if you were born at 11 PM in New York but view your age in Tokyo time (14 hours ahead), it might show you're one day older. The calculator performs all calculations in the selected timezone for consistency.