How to Calculate Age from Date of Birth — Exact Years, Months, and Days
Learn how to calculate your exact age from your date of birth, including leap year handling, zodiac sign detection, and birthday countdown. Includes a free online age calculator.
Want to know your exact age right now? Use the free Age Calculator — enter your date of birth and instantly see your age in years, months, days, weeks, and total hours, plus your zodiac sign and next birthday countdown.
The Age Calculation Formula
Age is calculated by finding the difference between your date of birth and today's date:
- Start with the current year minus your birth year
- If today's month and day are before your birth month and day, subtract 1
- The remaining months and days give your sub-year age
For example: born June 15, 1995, and today is February 28, 2026. Years = 2026 - 1995 = 31, but since February 28 is before June 15, subtract 1. Age = 30 years, 8 months, 13 days.
Why Leap Years Matter
A leap year adds February 29, making that year 366 days instead of 365. When calculating total days lived, each leap year in your lifetime adds one extra day. An accurate age calculator counts these correctly.
If you were born on February 29 (leap day), your birthday falls on February 28 in non-leap years for most legal and practical purposes.
What the Age Calculator Shows
- Exact age in years, months, and days
- Total days, weeks, and hours lived (updates live every second)
- The day of the week you were born
- Your Western zodiac sign (sun sign)
- Your Chinese zodiac animal based on birth year
- Countdown to your next birthday
- Countdown to your next milestone birthday (30, 40, 50, etc.)
Western Zodiac Signs by Birthday
| Sign | Dates | Sign | Dates |
|---|---|---|---|
| Aries | Mar 21 – Apr 19 | Libra | Sep 23 – Oct 22 |
| Taurus | Apr 20 – May 20 | Scorpio | Oct 23 – Nov 21 |
| Gemini | May 21 – Jun 20 | Sagittarius | Nov 22 – Dec 21 |
| Cancer | Jun 21 – Jul 22 | Capricorn | Dec 22 – Jan 19 |
| Leo | Jul 23 – Aug 22 | Aquarius | Jan 20 – Feb 18 |
| Virgo | Aug 23 – Sep 22 | Pisces | Feb 19 – Mar 20 |
Privacy and Security
The Age Calculator runs entirely in your browser. Your date of birth is never sent to any server or stored anywhere. The calculation happens locally using JavaScript.
Related Tools
- Date Difference Calculator — find days between any two dates, including working days
- Unix Timestamp Converter — convert dates to and from epoch time
FAQs
How do I calculate my exact age from my date of birth?
Subtract your birth date from today's date. Count full years first, then remaining months, then remaining days. Use the free Age Calculator to get your exact age in years, months, days, weeks, and total hours instantly.
How are leap years handled in age calculation?
Leap years add an extra day (February 29) every 4 years. A correct age calculator accounts for this when counting total days lived. If you were born on February 29, your birthday is counted on February 28 in non-leap years.
How do I find my zodiac sign from my birthday?
Your Western zodiac sign is determined by your birth month and day. For example, July 23 – August 22 is Leo. The Age Calculator automatically shows your zodiac sign when you enter your date of birth.
How many days old am I?
Multiply your age in years by 365.25 (to account for leap years) and add the days for remaining months. The Age Calculator shows your exact total days lived alongside years, months, and weeks.
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