Age Calculator
– – years
History
Your results will appear here. Tap Use on any of them to carry it into the next calculation, in this calculator or another one. History is kept while this tab is open.
Enter a date of birth and press Calculate: this online age calculator counts full years, then months and days, to today or any date you pick. Someone born Mar 15, 1990 is 36 years 7 months 19 days old on Nov 3, 2026.
How Old Am I?
Age on is already set to today, so as a how old am I calculator it needs just one date: pick your date of birth and press Calculate. The answer comes in whole years first, then months, then days. Born Mar 15, 1990? On Nov 3, 2026 that's 36 years 7 months 19 days.
The dates you enter are not sent anywhere. Tap the result to copy it, or press Use to take the whole years into another calculator.
Age on a Specific Date
Change Age on to a past or future date and the page works as an age at date calculator: how old someone was then, or will be. How old will I be in 2030? Set Age on to a day in 2030.
If you were born Mar 15, 1990, on Jan 1, 2000 you were 9 years 9 months 17 days old.
A date of birth after Age on is an error, not a negative age. Fix either date and press Calculate.
Age in Months, Weeks and Days
Under the age sits a line of totals since birth: full months, full weeks and days. For Mar 15, 1990 to Nov 3, 2026 it reads 439 months · 1 911 weeks · 13 382 days.
So one line answers how many days old am I, and how many weeks or months. Weeks are full weeks, without the leftover days. Age in days counts calendar days from the date of birth to Age on, which is all a days old calculator does.
Press Calculate with a new Age on and the totals move with it.
How Age Is Calculated
The age calculator formula, part by part:
age = whole years, then whole months, then the days left over
a month = a calendar month, not 30 days
short month = no matching day means the month's last day: born Jan 31, 2026, on Feb 28, 2026 it's 1 month
Feb 29 = the birthday is Mar 1 in a non-leap year: born Feb 29, 2000, it's 24 years 11 months 30 days on Feb 28, 2025 and 25 years on Mar 1, 2025
total days = calendar days from the date of birth to Age on; weeks = days ÷ 7, rounded down
Same arithmetic as the date calculator, except Feb 29. There, Feb 29, 2000 to Feb 28, 2025 is 25 years: it measures a gap between two dates, not a birthday.
Change a date and press Calculate again. Until you do, the old result stays dimmed.
Chronological Age
Schools and test forms call this chronological age: years, months and days on the day of the test. To use the page as a chronological age calculator, put the test date in Age on. For someone born Mar 15, 1990 and tested on Jan 1, 2000, the result is 9 years 9 months 17 days.
Examples
An age on Nov 3, 2026, an age on a past date and a Feb 29 birthday. For a group's average age, use the average calculator.
| You enter | Age | Also shown |
|---|---|---|
| Born Mar 15, 1990 · on Nov 3, 2026 | 36 years 7 months 19 days | 439 months · 1 911 weeks · 13 382 days · next birthday Mar 15, 2027, in 132 days · turning 37 · born on a Thursday |
| Born Mar 15, 1990 · on Jan 1, 2000 | 9 years 9 months 17 days | 117 months · 511 weeks · 3 579 days · next birthday Mar 15, 2000, in 74 days · turning 10 · born on a Thursday |
| Born Feb 29, 2000 · on Feb 28, 2025 | 24 years 11 months 30 days | 299 months · 1 304 weeks · 9 131 days · next birthday Mar 1, 2025, in 1 day · turning 25 · born on a Tuesday |
FAQ
What is my age right now?
Pick your date of birth and press Calculate; Age on is already set to today. If you were born Mar 15, 1990, the display reads 36 years 7 months 19 days on Nov 3, 2026.
How do I calculate age from a date of birth?
Count the full years up to the last birthday, then the full months after it; what's left is days. The calculator does all three once you enter the date of birth and press Calculate.
How many days old am I?
It's the last number on the totals line. Someone born Mar 15, 1990 is 13 382 days old on Nov 3, 2026.
When is my half birthday?
Six calendar months after your birthday, so Mar 15 gives Sep 15. A short month uses its last day: Aug 31 gives Feb 28, 2027, or Feb 29, 2028 in a leap year. The calculator itself doesn't show it.
What is chronological age?
It's your age in years, months and days on a set date, usually a test date; the Chronological Age section above shows how to get it.