Date Utility
Age
Calculator
Exact Age
0y 0m 0d
Next Birthday
— days
Find your exact age down to the day. Enter your date of birth and the calculator instantly shows your age in years, months and days, plus total days, weeks and hours alive. It also reveals what day of the week you were born on, your Western zodiac sign, your Chinese zodiac animal and how many days remain until your next birthday. Change the end date to calculate the age difference between any two dates.
Your Details
Your Age
0 years, 0 months, 0 days
Years
0
Months
0
Days
0
Total Days
0
Total Weeks
0
Total Hours
0
Fun Facts
Next Birthday
—
Born On
—
Zodiac Sign
—
Chinese Zodiac
—
How the age calculator works
Enter your date of birth using the date picker. The calculator defaults the end date to today, but you can change it to any date to find the exact difference between two dates.
The tool calculates your age by counting complete years from your birth date to the target date, then complete months within the remaining period, then leftover days. This gives you the same result you would get counting on a calendar, properly handling months with 28, 29, 30 or 31 days.
Total days are calculated by finding the difference in milliseconds between the two dates and dividing by the number of milliseconds in a day (86,400,000). Total weeks and total hours are derived from the total day count.
The calculator also identifies the day of the week you were born, your Western zodiac sign based on your birth month and day, and your Chinese zodiac animal based on the 12-year cycle. A countdown shows how many days remain until your next birthday.
What you need to know about age calculation
Age calculation seems straightforward, but varying month lengths and leap years introduce complexity. February has 28 days in common years and 29 in leap years. Months range from 28 to 31 days, meaning the number of days in "one month" depends on which month you are counting through.
A leap year occurs every 4 years, except for century years that are not divisible by 400. So 2000 was a leap year, but 1900 was not. If you were born on February 29, your birthday only occurs once every four years on the exact date. In non-leap years, most people celebrate on either February 28 or March 1.
In most legal contexts in the United States, a person's age increases by one year on their birthday. For age verification purposes, the exact time of birth is generally not considered — only the calendar date matters. This calculator follows the same convention, counting whole calendar days.
The Western zodiac divides the year into 12 signs based on the sun's position. The Chinese zodiac follows a 12-year cycle, with each year assigned an animal. Your Chinese zodiac animal is determined by your birth year, though the traditional Chinese calendar starts in late January or February.
Frequently asked questions
How do I calculate my exact age?
Enter your date of birth into the age calculator above and it will compute your exact age in years, months and days. The calculation accounts for varying month lengths and leap years, giving you a precise result down to the day.
What day of the week was I born on?
Enter your date of birth and the calculator will tell you the exact day of the week you were born on. It uses the date's position in the calendar to determine whether it was a Monday, Tuesday or any other day.
How many days until my next birthday?
The age calculator automatically shows a countdown to your next birthday. It finds the next occurrence of your birth month and day, then counts the days from today. If your birthday is today, it shows zero days remaining.
Does the age calculator account for leap years?
Yes. The calculator uses actual calendar dates rather than fixed day counts, so leap years on February 29 are handled correctly. If you were born on Feb 29, your next birthday falls on March 1 in non-leap years for the countdown.
How do I find my zodiac sign from my birthday?
Enter your date of birth and the calculator displays your Western zodiac sign based on the month and day you were born. It also shows your Chinese zodiac animal based on your birth year's position in the 12-year cycle.
How do I calculate age between two specific dates?
Change the "Calculate to" date field from today's date to any date you want. The calculator will show the exact difference in years, months, days, total days, total weeks and total hours between the two dates you choose.