How do I calculate my age from my date of birth?

Subtract your birth year from the current year. If your birthday has not happened yet this year, subtract one more year from that total. Then count the months and days separately using the same subtract-and-borrow method. This tool does all of that automatically. You just get the finished answer.

Can I calculate my age on a specific date?

Yes. Instead of leaving the calculate-as-of field on today, pick any date, past or future, and the tool works out your age as of that day. Use this for school enrollment cutoffs, immigration age requirements, or figuring out how old you will be on a future date like a wedding or retirement.

How does this handle leap years?

Leap years are built into the calendar math, not added as an afterthought. If someone's birthday is February 29, this tool treats it as February 28 in non-leap years for counting elapsed years, the same convention most legal and administrative systems use, while still calculating the exact day count correctly underneath.

What is chronological age?

Chronological age is the time that has passed since birth, measured in the calendar: years, months, and days. It is different from biological age, which estimates how old a body seems rather than how long a person has actually been alive. When a form or a doctor asks for your age, chronological age is what they mean.

How is Korean age different from international age?

Korean age starts at one, not zero, on the day someone is born, and everyone's age increases together on New Year's Day instead of on individual birthdays. Depending on birth month, that can put Korean age one or two years ahead of the international age most of the world uses. Toggle Also show Korean age to see both numbers at once.

How do I calculate age difference between two people?

Switch to the Age Difference tab, enter both birth dates, and the calculator returns the gap as years, months, and days, plus a flat day count if you need one number instead of three. It works the same way whether the gap is a few months or several decades.

How accurate is this online tool?

It is accurate to the day, using real calendar date math rather than a simplified days-divided-by-365 estimate. Leap years, varying month lengths, and the borrow-a-month logic are all handled correctly. The one thing it cannot account for is a wrong birth date typed in.

How do I calculate age in Excel?

Put the birth date in a cell, then wrap it in Excel's DATEDIF function with "Y", "YM", and "MD" as the unit arguments to pull out years, months, and days separately. The full formula is in the Excel section above. It is the same calendar-based approach this tool uses, just typed out manually.

Yes. Everything runs in your browser using JavaScript. Your birth date never leaves your device. There are no servers processing your information and no account required. You can disconnect from the internet after loading the page and the calculator still works.

Can I use this for my pet?

Yes. Click the Pet Age tab, choose dog or cat, and enter how many years old your pet is. The tool converts to human-equivalent age using the standard veterinary formula, not the old seven dog years equals one human year shortcut.

Wie alt ist jemand, geboren 1987? Altersrechner

Your date of birth

Date of birth

Calculate age as of

Also show Korean age

Results

Total days: 14,333
Total weeks: 2,047
Total months: 470
Total hours: 343,992
Seconds lived: 0

1987 age range (2026)

	Alter
Alter nach dem Geburtstag (frühestes Datum im Jahr)	39
Alter vor dem Geburtstag (spätestes Datum im Jahr)	38

Browse 1987 by month

january 1987 february 1987 march 1987 april 1987 may 1987 june 1987 july 1987 august 1987 september 1987 october 1987 november 1987 december 1987

Example dates in 1987

Geburtsdatum	Aktuelles Alter	Calculator
1. Januar 1987	39	Open
15. Juni 1987	39	Open
11. September 1987	39	Open
31. Dezember 1987	38	Open

All dates in 1987 (sample)

Date	Page
1. Januar 1987	january-1-1987
15. Januar 1987	january-15-1987
31. Januar 1987	january-31-1987
1. Februar 1987	february-1-1987
15. Februar 1987	february-15-1987
28. Februar 1987	february-28-1987
1. März 1987	march-1-1987
15. März 1987	march-15-1987
31. März 1987	march-31-1987
1. April 1987	april-1-1987
15. April 1987	april-15-1987
30. April 1987	april-30-1987
1. Mai 1987	may-1-1987
15. Mai 1987	may-15-1987
31. Mai 1987	may-31-1987
1. Juni 1987	june-1-1987
15. Juni 1987	june-15-1987
30. Juni 1987	june-30-1987
1. Juli 1987	july-1-1987
15. Juli 1987	july-15-1987
31. Juli 1987	july-31-1987
1. August 1987	august-1-1987
15. August 1987	august-15-1987
31. August 1987	august-31-1987
1. September 1987	september-1-1987
15. September 1987	september-15-1987
30. September 1987	september-30-1987
1. Oktober 1987	october-1-1987
15. Oktober 1987	october-15-1987
31. Oktober 1987	october-31-1987
1. November 1987	november-1-1987
15. November 1987	november-15-1987
30. November 1987	november-30-1987
1. Dezember 1987	december-1-1987
15. Dezember 1987	december-15-1987
31. Dezember 1987	december-31-1987

Altersmeilensteine

Alter	Jahr erreicht
1	1988
5	1992
10	1997
13	2000
16	2003
18	2005
21	2008
25	2012
30	2017
40	2027
50	2037

So wird berechnet

Das Kalenderalter zählt vollendete Geburtstage. Grob: Referenzjahr minus Geburtsjahr, minus 1 wenn der Geburtstag noch aussteht.
Genaues Alter = Jahre + Monate + Tage zwischen Geburts- und Referenzdatum, mit korrekter Monatslänge.

Age = Reference date − Birth date

Weeks ≈ total days ÷ 7. Hours = total days × 24. Minutes = total hours × 60 (exact for whole-day spans).

Nahe Geburtsjahre

1985 1986 1987 1988 1989