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 1945? Altersrechner

Your date of birth

Date of birth

Calculate age as of

Also show Korean age

Results

Total days: 29,673
Total weeks: 4,239
Total months: 974
Total hours: 712,152
Seconds lived: 0

1945 age range (2026)

	Alter
Alter nach dem Geburtstag (frühestes Datum im Jahr)	81
Alter vor dem Geburtstag (spätestes Datum im Jahr)	80

Browse 1945 by month

january 1945 february 1945 march 1945 april 1945 may 1945 june 1945 july 1945 august 1945 september 1945 october 1945 november 1945 december 1945

Example dates in 1945

Geburtsdatum	Aktuelles Alter	Calculator
1. Januar 1945	81	Open
15. Juni 1945	81	Open
11. September 1945	81	Open
31. Dezember 1945	80	Open

All dates in 1945 (sample)

Date	Page
1. Januar 1945	january-1-1945
15. Januar 1945	january-15-1945
31. Januar 1945	january-31-1945
1. Februar 1945	february-1-1945
15. Februar 1945	february-15-1945
28. Februar 1945	february-28-1945
1. März 1945	march-1-1945
15. März 1945	march-15-1945
31. März 1945	march-31-1945
1. April 1945	april-1-1945
15. April 1945	april-15-1945
30. April 1945	april-30-1945
1. Mai 1945	may-1-1945
15. Mai 1945	may-15-1945
31. Mai 1945	may-31-1945
1. Juni 1945	june-1-1945
15. Juni 1945	june-15-1945
30. Juni 1945	june-30-1945
1. Juli 1945	july-1-1945
15. Juli 1945	july-15-1945
31. Juli 1945	july-31-1945
1. August 1945	august-1-1945
15. August 1945	august-15-1945
31. August 1945	august-31-1945
1. September 1945	september-1-1945
15. September 1945	september-15-1945
30. September 1945	september-30-1945
1. Oktober 1945	october-1-1945
15. Oktober 1945	october-15-1945
31. Oktober 1945	october-31-1945
1. November 1945	november-1-1945
15. November 1945	november-15-1945
30. November 1945	november-30-1945
1. Dezember 1945	december-1-1945
15. Dezember 1945	december-15-1945
31. Dezember 1945	december-31-1945

Altersmeilensteine

Alter	Jahr erreicht
1	1946
5	1950
10	1955
13	1958
16	1961
18	1963
21	1966
25	1970
30	1975
40	1985
50	1995

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

1943 1944 1945 1946 1947