Age Calculator
If you only know the age in whole years, the true birth date could fall anywhere within the surrounding 12 months.
What is an age calculator?
An age calculator tells you exactly how old someone is. You put in a date of birth, and it shows the age in years, months, and days — right up to today, or any date you choose.It's faster and more accurate than counting in your head, especially when you need the exact number of months or days.
How to use this calculator
This calculator has four tabs at the top. Pick the one that matches what you want to do, fill in the date or dates, and the answer shows up right away — no button to click. If you want to check your age in a different system, like Korean or Chinese, you can switch that option too. All four tabs work the same way: enter a date, get your answer instantly.
My age
Enter your date of birth. Your age shows instantly in years, months, and days.
Age gap
Enter two birth dates. See exactly how much older or younger one person is than the other.
Age on a date
Enter a birth date and a past or future date. Find out how old someone was — or will be — on that day.
Find birth date
Know someone's age but not their exact birthday? Enter the age and get an estimated birth date range.
Western, Korean, and Chinese age — what's the difference?
Most countries use Western age: you start at 0 when you're born, and your age goes up by one on each birthday.In the Korean system, you are 1 year old the day you're born. Your age then goes up by one every January 1st — not on your actual birthday. So a baby born in December could already be 2 years old just a few weeks later by Korean count.The Chinese traditional system is similar to Korean but uses the lunar new year instead of January 1st. It's used less often today but still appears in some cultural contexts.
Common questions
Why does my age show 0 years when I was just born?
In the Western system, you are 0 years old until your first birthday. This is normal.
What if I was born on February 29 (a leap day)?
Leap day birthdays are counted differently by different countries. Most countries treat February 28 or March 1 as your birthday in non-leap years. This calculator uses February 28.
Can I use this to find someone's age on a past date?
Yes. Use the "Age on a date" tab. Enter the birth date and the past date you're curious about.
How is the age gap calculated?
The age gap is the difference between two birth dates. It shows the gap in days, weeks, and months. It does not depend on today's date — it's simply the distance between the two birthdays.
How accurate is this calculator?
Very accurate. It counts the exact number of days between dates, taking into account leap years and month lengths.