Age Calculator
Find your exact age in years, months and days, with total months, weeks, days and hours, plus a countdown to your next birthday. Everything runs in your browser — your date of birth is never sent anywhere and nothing is stored.
How to use the age calculator
- Pick your date of birth.
- Leave age at date as today, or change it to any past or future date.
- Your exact age and all totals update instantly as you type.
The age is calculated the calendar-correct way: whole years, then remaining
months, then remaining days — the same method used on official
forms — so leap years and uneven month lengths are handled for you.
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Frequently asked questions
How is my exact age calculated?
Your age is worked out the calendar-correct way, not by simple day division. We subtract the day, then the month, then the year, borrowing days from the previous month and months from the year where needed — so the result is the real number of years, months and days you have lived.
Can I calculate my age on a past or future date?
Yes. The second field, age at date, defaults to today but you can change it to any date. The calculator then shows how old you were (or will be) on that date, which is handy for forms, anniversaries and planning.
How are total months, weeks, days and hours figured out?
The totals count the whole span between your date of birth and the chosen date. Total days is the exact number of calendar days (leap years included); weeks and hours derive from that, and total months counts complete months elapsed.
What does the next birthday countdown show?
It shows how many days remain until your next birthday from the selected date. If the date is your birthday, it reads 0 days. Leap-day birthdays (29 February) are handled sensibly on common years.
Is my date of birth sent anywhere?
No. Every calculation runs entirely in your browser — your date of birth is never uploaded to a server and nothing is stored. It is safe to use for private information.
Why do I see a validation message?
If your date of birth is after the age-at date (for example a birth date in the future), the age cannot be computed and a friendly message appears. Correct the dates so the birth date comes first and the result updates instantly.