Age Calculator
Age = Today − Date of BirthCurrent date − 2000-01-01 = years, months and days
Free online tool
Age Calculator
Enter your birth date to see your precise age broken down into years, months, days, weeks and total days lived.
Instant calculation
Calculate Your Age
Enter your date of birth to calculate your exact age.
Your result
Calculation
Your numbers stay in this browser. Nothing is uploaded or saved.
Three clear steps
How to use this calculator
- 01
Enter your birth year
Type the year you were born (for example, 1990).
- 02
Enter month and day
Type your birth month (1-12) and day (1-31).
- 03
See your exact age
Select Calculate Age to see your age in years, months, days, weeks and total days.
The formula
How this calculation works
Subtract your birth date from today's date. Count the years first, then the remaining months, then the remaining days. Leap years and month lengths are accounted for automatically.
Check the method
Worked examples
Each example follows the same formula used by the calculator.
Born Jan 1, 2000 — how old today?
Current date − 2000-01-01 = years, months and daysDepends on today's date — try it aboveBorn Feb 29, 2000 — age in a non-leap year?
Feb 29 birthdays are treated as Mar 1 in non-leap years for age calculationYour age updates on Mar 1 in non-leap yearsCommon questions
Questions about this calculation
How is my exact age calculated?
Your age is calculated by comparing your birth date with today's date. First, the full years are counted, then the remaining months, then the remaining days. Leap years and month lengths are all handled automatically.
Why does my age in days not divide evenly by 365?
Calendar years have 365 or 366 days. The total includes leap days, which occur in years divisible by 4 (except century years not divisible by 400).
What if I enter an invalid date like Feb 30?
The calculator validates your input. Feb 30 does not exist, so you would see an error asking you to enter a valid date.
Does the calculator work for dates before 1900?
Birth-date calculators accept years from 1900 to 2100. The Date Difference Calculator accepts any year from 1 to 9999 for general purpose use.
How are weeks calculated from my age?
Total weeks = floor(Total days / 7). The floor division gives the number of complete 7-day periods you have lived.
Continue calculating