-
Use Cases
-
Resources
-
Pricing
How Many Days Old Am I? Days Alive Calculator
How many days have you been alive? Enter your date of birth to see your age in days, and in years, months, weeks, hours, minutes and seconds too. It also gives the dates you turn 10,000 days, 1,000 weeks and a billion seconds old.
Try an example
- , born on August 4, 1961, was 17,336 days old when he was sworn in as president on January 20, 2009: 47 years, 5 months and 16 days.
- , born on August 5, 1930, was 14,229 days old when he stepped onto the Moon on the evening of July 20, 1969, US time. That is 2,032 weeks and 5 days.
- lived 13,096 days, from January 27, 1756 to December 5, 1791. He never reached 15,000.
- : 10,000 days old on Wednesday, May 19, 2027, and a billion seconds old on September 9, 2031, at 1:46:40 in the morning if born at midnight.
How the days are counted
You are 0 days old on the day you are born and 1 day old the next day, the same way you are 0 years old until your first birthday. The calculator turns both dates into a day count (the Julian Day Number astronomers use) and subtracts, so leap years are counted exactly: someone born on January 1, 2000 has lived through every February 29 since, starting with the one in 2000.
Weeks are the days divided by 7, with the days left over. Hours, minutes and seconds are the days times 24, 1,440 and 86,400, counted from the time of day you were born, so add the hours since then for the exact figure. They leave out the 27 leap seconds added to clocks since 1972.
Age in months
A month is not a fixed number of days, so age in months is counted the way an age in years is: whole months from the date of birth, then the days left over. A baby born on January 31 is 1 month old on February 28 (or 29 in a leap year), the last day of the shorter month, and 2 months old on March 31. Someone born on February 29 is counted a year older on February 28 in a common year.
Doctors and parents usually give a baby's age in weeks until about 3 months, then in months until 2 years. The calculator shows both.
Milestone days
Some people celebrate round numbers instead of birthdays. You turn 10,000 days old at about 27 years and 4 months, 20,000 days at about 54 years and 9 months, and 1,000 weeks at 19 years and about 2 months. A billion seconds is 11,574 days, 1 hour, 46 minutes and 40 seconds, about 31 years and 8 months. The calculator lists each of these dates, past and future, for any birthday.
Dates before 1582
The calculator reads dates in the Gregorian calendar, which began on October 15, 1582, and refuses earlier ones. For someone born before then, use the age at death calculator, which reads older dates in the Julian calendar and also gives the total in days.
Related tools
To find the weekday you were born on, use the day of the week calculator. To find a date a number of days from today, such as 90 days on, use the days from today calculator. To work out a birth year from an age, use the birth year calculator.
Your days on a timeline
Ten thousand days is a lot of history. To lay out the moments that filled yours, Preceden can put your life on a timeline.