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 2004 ?

Your date of birth

Date of birth

Calculate age as of

Also show Korean age

Results

Total days: 8,122
Total weeks: 1,160
Total months: 266
Total hours: 194,928
Seconds lived: 0

2004 age range (2026)

	Âge
Âge après l'anniversaire (premier jour de l'année)	22
Âge avant l'anniversaire (dernier jour de l'année)	21

Browse 2004 by month

january 2004 february 2004 march 2004 april 2004 may 2004 june 2004 july 2004 august 2004 september 2004 october 2004 november 2004 december 2004

Example dates in 2004

Date de naissance	Âge actuel	Calculator
1 janvier 2004	22	Open
15 juin 2004	22	Open
10 septembre 2004	22	Open
31 décembre 2004	21	Open

All dates in 2004 (sample)

Date	Page
1 janvier 2004	january-1-2004
15 janvier 2004	january-15-2004
31 janvier 2004	january-31-2004
1 février 2004	february-1-2004
15 février 2004	february-15-2004
29 février 2004	february-29-2004
1 mars 2004	march-1-2004
15 mars 2004	march-15-2004
31 mars 2004	march-31-2004
1 avril 2004	april-1-2004
15 avril 2004	april-15-2004
30 avril 2004	april-30-2004
1 mai 2004	may-1-2004
15 mai 2004	may-15-2004
31 mai 2004	may-31-2004
1 juin 2004	june-1-2004
15 juin 2004	june-15-2004
30 juin 2004	june-30-2004
1 juillet 2004	july-1-2004
15 juillet 2004	july-15-2004
31 juillet 2004	july-31-2004
1 août 2004	august-1-2004
15 août 2004	august-15-2004
31 août 2004	august-31-2004
1 septembre 2004	september-1-2004
15 septembre 2004	september-15-2004
30 septembre 2004	september-30-2004
1 octobre 2004	october-1-2004
15 octobre 2004	october-15-2004
31 octobre 2004	october-31-2004
1 novembre 2004	november-1-2004
15 novembre 2004	november-15-2004
30 novembre 2004	november-30-2004
1 décembre 2004	december-1-2004
15 décembre 2004	december-15-2004
31 décembre 2004	december-31-2004

Étapes d'âge

Âge	Année atteinte
1	2005
5	2009
10	2014
13	2017
16	2020
18	2022
21	2025
25	2029
30	2034
40	2044
50	2054

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

2002 2003 2004 2005 2006