Age Calculator
Calculate exact age from a date of birth: years, months and days, total days lived, next birthday and weekday, with 29 February birthdays handled. Private.
How to use Age Calculator
- 1Enter the date of birth as YYYY-MM-DD, or use the date picker.
- 2Leave Age at empty to use today's date, or set any date to measure to.
- 3Read the age and the next birthday, or switch to Difference or Add/Subtract for other date jobs.
What makes it better
- Age in years, months and days, plus total days, weeks, months and hours lived
- Next birthday with its weekday, the age being turned and the days remaining
- 29 February birthdays follow a rule you choose (28 February or 1 March) and the page explains it
- Measure to today or to any date, such as an admission cut-off
- Everything is calendar-based, so the answer does not depend on your time zone
About Age Calculator
Enter a date of birth and the age is shown in years, months and days, together with the total days, weeks, months and hours lived, the date and weekday of the next birthday and how many days remain. Age is measured to today by default, or to any date you choose, such as a cut-off date for a form. People born on 29 February are handled with a stated rule rather than silently.
Common uses
- Check eligibility for a form, exam or scheme that needs an age on a given date.
- Find the age of a child in months and days for a growth or vaccination record.
- Plan a birthday by seeing the weekday it falls on.
- Work out how many days someone has been alive for a card or a celebration.
Example
Input
Born 1990-05-15, age on 2024-03-20
Result
Born: 1990-05-15 (Tuesday) Age on 2024-03-20: 33 years, 10 months, 5 days Total days lived: 12,363 Total weeks: 1,766 Total months: 406 Total hours: 296,712 Next birthday: Wednesday, 15 May 2024 (turning 34) Days to next birthday: 56
Good to know
- Whether someone born on 29 February turns a year older on 28 February or 1 March in common years is a legal convention that differs between countries. The page lets you pick and states the rule in use.
- Today's date is read from your device when the page opens, so a wrong device clock gives a wrong age. Type a date in Age at to override it.
- The calculation uses the Gregorian calendar for every date, including old ones, so very historical birth dates are not adjusted for earlier calendars.
Age Calculator FAQ
How is exact age calculated from a date of birth?
The page counts complete years since the birth date, then complete months since the last birthday, then the leftover days. A person born on 15 May 1990 is 33 years, 10 months and 5 days old on 20 March 2024.
How old is someone born on 29 February?
In leap years the birthday is 29 February. In other years it is counted on 28 February or on 1 March, depending on the rule you pick in the options, and the page prints which rule produced the answer.
Can I find my age on a past or future date?
Yes. Set the Age at date to the cut-off you need, such as the first day of a school year or a retirement date. A date before the birth date gives a message instead of a negative age.
How many days old am I?
Total days lived is shown under the age. It is the number of calendar days between the birth date and the Age at date, so it increases by exactly one each day without any time-of-day rounding.
When is my next birthday and what day of the week is it?
The page shows the date, the weekday, the age you will turn and the number of days left. If the birthday is today, it says so and shows zero days.