Age Calculator
Enter your date of birth to calculate your exact age in years, months and days, plus total days lived, total weeks, and a countdown to your next birthday — updated live as you type.
How to Use the Age Calculator
- Enter your date of birth in the first field.
- By default, "Calculate Age As Of" is set to today — change it if you want your age on a different date.
- Your exact age in years, months and days appears instantly.
- Check the stat cards below for total days lived, total weeks lived, and how many days remain until your next birthday.
Why Use This Tool?
How is the exact age calculated?
This tool performs a calendar-aware calculation rather than simply dividing total days by 365. It compares year, month and day values between your birth date and the "as of" date, borrowing days and months where needed, so the years/months/days breakdown always matches how a calendar actually works — including leap years.
Why might I want my age on a date other than today?
Age requirements for school enrollment, sports eligibility, visa applications, retirement benefits and legal contracts are often calculated "as of" a specific cutoff date rather than today. Changing the "as of" date lets you check your exact age on that specific day.
What do "total days lived" and "total weeks lived" mean?
These are simple running totals — the full number of days (or weeks) between your birth date and the "as of" date, without breaking them into years and months. They're a fun way to see milestones like your 10,000th day or 1,000th week alive.
Is my birth date stored or shared anywhere?
No. All calculations run locally in your browser with JavaScript. Your date of birth is never transmitted to a server, logged or saved — it disappears the moment you leave or refresh the page.