Age Calculator
Calculate your exact age in years, months and days from your date of birth. Also shows total days lived, day of week you were born, and days until your next birthday.
Your result will appear here.
Age Calculator online
Find out exactly how old you are — down to the day. Enter your date of birth and an optional reference date (defaults to today) to get your precise age in years, months and days, plus total days lived, the day of the week you were born, and a countdown to your next birthday.
How it works
The calculator uses the browser's native Date object to compute the exact calendar difference between two dates. It does not simply divide total days by 365.25 — instead it calculates the true calendar difference accounting for leap years, varying month lengths, and the exact day/month/year boundaries. The algorithm finds the number of whole years, then whole months, then remaining days between the two dates.
Worked example
Born 15 March 1990, today 8 October 2026: the calculator counts 36 full years (15 Mar 1990 → 15 Mar 2026), then 6 full months (15 Mar → 15 Sep), then 23 days (15 Sep → 8 Oct). Result: 36 years, 6 months, 23 days. Total days lived: 13,356. Born on a Thursday. Next birthday in 158 days (15 March 2027).
Practical tips
- Use the Reference date field to calculate age on a specific past or future date (e.g., "How old was I on my wedding day?").
- For people born on 29 February, the calculator treats 28 February as the birthday in non-leap years (common legal convention).
- The Day of week born and Days until next birthday are bonus features — handy for party planning.
- This tool uses your browser's local time zone for "today". If you need a specific time zone, adjust the reference date accordingly.
Privacy and browser processing
Whenever practical, DailyWebKit processes input locally in your browser. Tools that need network data can depend on external services, browser permissions and CORS. Do not enter confidential information into a third-party network service.
Frequently asked questions
Why isn't age just "total days ÷ 365"?
Because years have different lengths (leap years) and months vary from 28 to 31 days. Dividing by 365 gives an approximation that can be off by weeks or months. This tool uses true calendar arithmetic.
What if I was born on 29 February?
In non-leap years the calculator treats 28 February as the birthday — the standard legal convention in most jurisdictions. The day count remains exact.
Can I calculate age on a specific past/future date?
Yes. Enter a Reference date (defaults to today). For example, set it to your wedding date to find out how old you were then.
Does the tool account for time zones?
The tool uses your browser's local date for "today". For historical or legal purposes where time zone matters, use the reference date to specify the exact calendar date you want.
Is this tool free?
Yes. It is free and does not require an account.
Does DailyWebKit upload my input?
No. It runs locally in your browser and your input is never uploaded.