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Age Calculator

Enter a date of birth and get the exact age in years, months, and days. Also shows the total days and weeks lived, and how many days until the next birthday.

Calculator Tools Runs locally No data sent
agebirthdaydatecalculator
Date of Birth
Enter a date of birth above to calculate age.

What is Age Calculator?

Age Calculator computes the exact number of years, months, and days between a date of birth and a reference date (today by default). It also shows the total days and weeks lived, and how many days remain until the next birthday.

How to Use Age Calculator

  1. Enter the date of birth using the date picker.
  2. The reference date defaults to today —change it to calculate age as of any date.
  3. View the exact age broken down into years, months, and days.
  4. Check the stats cards for total months, weeks, days lived, and next birthday countdown.

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Understand Age Calculation ▾
Example
Input Date of birth: 1990-06-15, as of: 2026-03-23
Output Age: 35 years, 9 months, 8 days | 13,066 days lived | Next birthday in 83 days
Common Use Cases
  • Calculate your exact current age for a medical or legal form
  • Find out how many days old you are
  • Check how many days until your next birthday
  • Calculate a child's age in months and days for a pediatric visit
Why Use This Tool
  • Gives the exact age in years, months, and days —not just years.
  • Useful for forms that ask for age in months, or for medical and legal contexts.
  • The 'as of' date lets you calculate historical or future ages.
  • Runs entirely in your browser —no data is sent anywhere.
Frequently Asked Questions
How is the age calculated?

The calculator counts full calendar years, months, and days from the date of birth to the reference date, accounting for varying month lengths.

Can I calculate age as of a past or future date?

Yes. Change the 'Calculate as of' date to any past or future date to see what the age was or will be on that day.

How is the next birthday calculated?

The next birthday is the nearest future occurrence of the birth month and day. If today is the birthday, it shows 'Today!'.

Does this account for leap years?

Yes. The calculator uses standard JavaScript date arithmetic which handles leap years correctly.