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.

Quel âge a quelqu'un né en 2001 ?

Your date of birth

Date of birth

Calculate age as of

Also show Korean age

Results

Total days: 9,219
Total weeks: 1,317
Total months: 302
Total hours: 221,256
Seconds lived: 0

2001 age range (2026)

	Âge
Âge après l'anniversaire (premier jour de l'année)	25
Âge avant l'anniversaire (dernier jour de l'année)	24

Browse 2001 by month

january 2001 february 2001 march 2001 april 2001 may 2001 june 2001 july 2001 august 2001 september 2001 october 2001 november 2001 december 2001

Example dates in 2001

Date de naissance	Âge actuel	Calculator
1 janvier 2001	25	Open
15 juin 2001	25	Open
11 septembre 2001	25	Open
31 décembre 2001	24	Open

All dates in 2001 (sample)

Date	Page
1 janvier 2001	january-1-2001
15 janvier 2001	january-15-2001
31 janvier 2001	january-31-2001
1 février 2001	february-1-2001
15 février 2001	february-15-2001
28 février 2001	february-28-2001
1 mars 2001	march-1-2001
15 mars 2001	march-15-2001
31 mars 2001	march-31-2001
1 avril 2001	april-1-2001
15 avril 2001	april-15-2001
30 avril 2001	april-30-2001
1 mai 2001	may-1-2001
15 mai 2001	may-15-2001
31 mai 2001	may-31-2001
1 juin 2001	june-1-2001
15 juin 2001	june-15-2001
30 juin 2001	june-30-2001
1 juillet 2001	july-1-2001
15 juillet 2001	july-15-2001
31 juillet 2001	july-31-2001
1 août 2001	august-1-2001
15 août 2001	august-15-2001
31 août 2001	august-31-2001
1 septembre 2001	september-1-2001
15 septembre 2001	september-15-2001
30 septembre 2001	september-30-2001
1 octobre 2001	october-1-2001
15 octobre 2001	october-15-2001
31 octobre 2001	october-31-2001
1 novembre 2001	november-1-2001
15 novembre 2001	november-15-2001
30 novembre 2001	november-30-2001
1 décembre 2001	december-1-2001
15 décembre 2001	december-15-2001
31 décembre 2001	december-31-2001

Étapes d'âge

Âge	Année atteinte
1	2002
5	2006
10	2011
13	2014
16	2017
18	2019
21	2022
25	2026
30	2031
40	2041
50	2051

Comment c'est calculé

L'âge en années compte les anniversaires complets. Estimation : année de référence − année de naissance, moins 1 si l'anniversaire n'a pas encore eu lieu.
Âge exact = années + mois + jours entre la naissance et la date de référence, avec emprunt sur le mois précédent si besoin.

Age = Reference date − Birth date

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

Années proches

1999 2000 2001 2002 2003