How old am I in days?

Enter your date of birth above. As a rule of thumb, multiply your age in years by 365.25: a 30-year-old has lived about 10,957 days.

When will I be one billion seconds old?

One billion seconds is 31 years, 251 days and about 1 hour 46 minutes, depending on how many leap days fall in between. The milestone table gives your exact date.

How do leap years affect my age?

They add a day to your total days roughly every four years. If you were born on February 29, most countries treat March 1 as your birthday in non-leap years for legal purposes; some use February 28.

Does the calculator use my time zone?

Yes. It uses your device's clock and time zone. Enter a time of birth for an exact count of hours and seconds.

Age in Days Calculator: How Many Days Have You Lived?

Age in Days Calculator

How many days you have been alive, with a live counter, and the dates of your 10,000th, 15,000th and 20,000th day.

Years, months, days

Total days

Total hours

Next birthday

Your milestones

Round numbers of days and seconds, and when you reach them.

Milestone	Date	From today

How age is calculated

Age in years, months and days counts whole calendar units: first the full years since your birthday, then full months since your last monthly anniversary, then the remaining days. That is why two people born 30 days apart can be "1 month" apart in one season and "30 days" in another: months have 28 to 31 days.

Totals in days, hours and seconds are simpler: they count the exact time elapsed. Every fourth year adds a leap day (except century years not divisible by 400, so 2000 was a leap year and 2100 will not be), which is why a year averages 365.2425 days.

Days and seconds in a lifetime

Age	About this many days	Hours	Seconds
1 year	365	8,766	31,556,952
10 years	3,652	87,658	315,569,520
18 years	6,574	157,785	568,025,136
21 years	7,670	184,082	662,695,992
25 years	9,131	219,146	788,923,800
30 years	10,957	262,975	946,708,560
40 years	14,610	350,633	1,262,278,080
50 years	18,262	438,291	1,577,847,600
65 years	23,741	569,778	2,051,201,880
80 years	29,219	701,266	2,524,556,160
100 years	36,524	876,582	3,155,695,200

Milestones worth celebrating

10,000 days arrives at about 27 years and 5 months. One billion seconds comes at 31 years, 8 months and a little over two weeks. 20,000 days is at about 54 years and 9 months. The table above lists yours with exact dates once you enter a date of birth.

Age and money

A few ages matter for your finances in the US: 26, when you leave a parent's health plan; 50, when 401(k) and IRA catch-up contributions start; 59½, when retirement accounts can be tapped without penalty; 62 to 70, the window for claiming Social Security; and 65, Medicare. The retirement calculator and 401(k) calculator start from your age.