Age Calculator
Enter your date of birth to find your exact age in years, months, and days, along with total days lived, your next birthday, and the day of the week you were born.
Calculate age on a specific past or future date instead of today
Showing an example for someone born January 1, 2000. Enter your own date of birth above to calculate your exact age.
You are
26 years, 6 months, 20 days
Born Saturday, January 1, 2000 (Saturday) · age as of Tuesday, July 21, 2026
You have been alive for
837,984,834
seconds and counting
Your Exact Age in Every Unit
Every value updates live. Click Copy to grab any number for a form, profile, or document.
Years (decimal)
26.55
Months
318
Weeks
1,385
Days
9,698
Hours
232,773
Minutes
13,966,413
Your Next Birthday
- Date
- Friday, January 1, 2027
- Falls on a
- Friday
- Days away
- 164
- You will turn
- 27
Day Milestones
- Days lived
- 9,698
- Next milestone
- 10,000 days
- Reached on
- Wed, May 19, 2027
- Days away
- 302
The Day You Were Born
Day of the week
Saturday
Zodiac sign
Capricorn
Chinese zodiac
Dragon
Generation
Generation Z
Birthstone
Garnet
Birth flower
Carnation
Zodiac uses the Western (tropical) dates. The Chinese zodiac animal is based on your birth year and shifts at Chinese New Year in late January or February, so births in that window may fall under the previous animal.
Your Age on a Different Scale
Your age on other planets
A "year" is one orbit around the Sun. Because every planet orbits at a different speed, your age changes on each one.
Mercury
110.2
years
Venus
43.2
years
Mars
14.1
years
Jupiter
2.24
years
Saturn
0.90
years
Roughly, in that time your body has…
1,117,313,040
heartbeats (~80 bpm)
223,462,608
breaths (~16 / min)
328
full moons since birth
These are approximate estimates for curiosity, using typical average rates — not medical or astronomical measurements.
How Age Is Calculated
Your age is the elapsed time from your date of birth to a reference date — usually today. The everyday way to express it is years, months, and days, and the reliable way to compute it is to work from the largest unit down, borrowing when a subtraction goes negative.
The manual method
- Subtract the years. Take this year minus your birth year.
- Subtract the months. If the current month is earlier in the year than your birth month, the result is negative — borrow one year (turn it into 12 months) and reduce the years by one.
- Subtract the days. If the current day of the month is earlier than your birth day, borrow the number of days in the previous month and reduce the months by one.
Worked example. Born November 15, 2006, measured on March 10, 2026. Years: 2026 − 2006 = 20. Months: March (3) − November (11) = −8, so borrow a year → 19 years and 4 months. Days: 10 − 15 = −5, so borrow February's days → the day count resolves inside that month. The result is 19 years, 3 months, and 23 days. This calculator does the same borrowing automatically, which is why the day number is never negative or impossible even when you were born on the 31st.
Age in Excel and Google Sheets
With your birth date in cell A1, the hidden DATEDIF function gives each piece:
=DATEDIF(A1, TODAY(), "Y")→ whole years=DATEDIF(A1, TODAY(), "YM")→ leftover months=DATEDIF(A1, TODAY(), "MD")→ leftover days=DATEDIF(A1, TODAY(), "D")→ total days lived
Why total days beats years for precision
Because leap years add a February 29 roughly every four years, a person's age in total days is a little more than their age in years multiplied by 365. When you need an exact figure — for a medical form, a legal document, or a database — the days, hours, and seconds breakdown above is the unambiguous one, since it counts real calendar time rather than rounding to whole years.
Age Systems Around the World
This calculator uses international age: you are zero at birth and gain a year on each birthday. It is the standard almost everywhere and the one used for legal and medical purposes.
Some traditions differ. The historical East Asian counting age considered a newborn to be one year old at birth, with everyone advancing a year at Lunar New Year rather than on their individual birthday — which could make a stated age one or even two years higher than the international count. These systems have faded from official use: South Korea standardized on international age in June 2023, and China, Japan, and Vietnam moved to it decades earlier. If someone quotes an age that seems a year or two off, a traditional counting system is often the reason.
Age Calculator FAQ
How do I calculate my age?
Enter your date of birth. This calculator subtracts your birth date from today, borrowing across months and years so the result is your exact age in years, months, and days — for example, 26 years, 6 months, and 20 days. To do it by hand, subtract the years, then the months, then the days; if the days come out negative, borrow the number of days in the previous month and reduce the months by one.
How many days old am I?
Your age in days is the total number of calendar days between your date of birth and today. This tool shows it live, along with your age in weeks, hours, minutes, and seconds. Because it counts real calendar days, leap days (February 29) are automatically included.
Does the age calculator count leap years?
Yes. It compares the actual calendar dates, so every leap day you have lived through is counted. That is why your age in total days is slightly more than your age in years times 365 — the extra days are the February 29ths.
How is age calculated at the end of a month, like being born on the 31st?
When your birth day does not exist in the target month (for example, born on the 31st and measuring on a month that has 30 days), the calculator counts a full month only once a matching or later day is reached. This mirrors the common convention used by date libraries, so the years-months-days breakdown never shows a negative or impossible day count.
How does it handle a February 29 (leap day) birthday?
In years that are not leap years, February 29 does not exist, so your birthday is marked on February 28 for the age count (some people instead celebrate on March 1). This calculator uses February 28 in common years, and your real leap-day birthday whenever the year is a leap year.
When is my next birthday and how many days away is it?
The calculator finds the next time your birth month and day occur on or after today, then shows the exact date, the weekday it falls on, how many days remain, and which birthday it will be. If today is your birthday, it says so.
What is my age in months or weeks?
Your age in whole months is your years multiplied by twelve plus the leftover months. Your age in weeks is your total days divided by seven. Both are shown in the breakdown and update live, and you can copy any value with one click.
Why do some countries calculate age differently?
Most of the world uses the "international age" this calculator shows: you are zero at birth and gain a year on each birthday. Some East Asian traditions historically used a "counting age" in which a person is one year old at birth and everyone advances at Lunar New Year, which can make the stated age one to two years higher. South Korea standardized on international age in 2023.
What is my zodiac sign based on my birthday?
Your Western (tropical) zodiac sign is set by the month and day you were born — for example, anyone born from March 21 to April 19 is an Aries. The calculator shows your sign, along with your birthstone, birth flower, Chinese zodiac animal, and the generation your birth year falls in.
How do I calculate age in Excel or Google Sheets?
Use DATEDIF. With the birth date in A1, =DATEDIF(A1, TODAY(), "Y") returns whole years, "M" returns whole months, and "D" returns total days. To build the full years-months-days phrase, combine =DATEDIF(A1,TODAY(),"Y") years, =DATEDIF(A1,TODAY(),"YM") months, and =DATEDIF(A1,TODAY(),"MD") days.