Age Calculator
Calculate your exact age in years, months, and days, or find the age between any two dates. Also shows total days lived, total weeks, and how many days until your next birthday.
How Age Is Calculated
Years = target year − birth year (adjusted for month/day)
Months = remaining months after full years
Days = remaining days after full months
Total days = (target date − birth date) in milliseconds ÷ 86,400,000
Total weeks = total days ÷ 7 (rounded down)
Day-count uses calendar month lengths, so months vary from 28 to 31 days. The "as of" date can be set to any future date to calculate a future age — useful for planning milestone birthdays or eligibility checks.
How to use
Date of birth
Enter your date of birth in the first field. The 'Age as of' field defaults to today but you can change it to any past or future date — useful for calculating how old you'll be on a specific date.
Next birthday countdown
The calculator automatically finds your next birthday from the 'as of' date and counts the days remaining.
Tips
- •Change 'Age as of' to a future date to find out how old you'll be on that day.
- •Use the Date Difference calculator if you need the time between two arbitrary dates without birthday information.