Age Calculator
Enter a date of birth to see an exact age today or on any other date, broken down into years, months and days, with totals in weeks, days and hours and a countdown to the next birthday.
Result
- Total months
- 437 months
- Total weeks
- 1,902 weeks and 2 days
- Total days
- 13,316 days
- Total hours
- 319,584 hours
- Born on a
- Sunday
- Next birthday
- May 20, 2027 (turning 37, in 198 days)
How the age calculator works
Age is the calendar time that has passed between a date of birth and another date. The calculator reports it the way people say it, as whole years, then whole months, then days, and also as simple totals: the number of months, weeks, days and hours lived. It also tells you the weekday you were born on and how many days remain until your next birthday.
Method and worked example
The age in years, months and days is found in three steps:
- Count the number of full years from the birth date. The year count increases on each birthday.
- From the last birthday, count full months. A month is complete on the same day of the following month.
- Count the remaining days.
Example: born May 20, 1990, age on November 1, 2026. The last birthday was May 20, 2026, so the person has completed 36 years. From May 20 to October 20 is 5 full months. From October 20 to November 1 is 12 days. The age is therefore 36 years, 5 months, 12 days. Counting every calendar day between the two dates gives 13,314 days, or 1,902 weeks exactly.
When the day of the month does not exist in the target month, the month end is used. For instance, one month after January 31 is February 28 (or February 29 in a leap year). This is the same convention used by most date libraries and by the date calculator on this site.
How to use this calculator
- Enter the date of birth. The second field defaults to today, so you immediately see the current age.
- To find an age on another date, such as the first day of school or the date of an exam, change “Age at this date”.
- Results update as you type. Use Reset to return to the example values.
Notes and limitations
- Only calendar dates are used, not times of day, so the result does not depend on the hour of birth or on time zones.
- Leap-day birthdays are counted on February 28 in common years. Some legal systems use March 1 instead.
- Some countries have traditional age-counting systems (for example “Korean age”, phased out for legal use in 2023) that give a different number. This calculator uses the international standard: you are 0 at birth and turn 1 on your first birthday.
- Need the number of weeks of pregnancy rather than an age? Use the due date calculator.
Frequently asked questions
How is age calculated exactly?
The calculator counts full years first, then full months, then the remaining days, the same way people state their age. Someone born on May 20, 1990 is 36 years, 5 months and 12 days old on November 1, 2026. Months are counted on the same day of the month, with month-end dates clamped when the target month is shorter.
What if I was born on February 29?
In years without a February 29, the calculator treats February 28 as the birthday, so your age increases on that day. Some countries (for example the UK) use March 1 for legal purposes instead, so an official document may differ by one day in common years.
Why does the total number of days not divide evenly into years?
Years are not all the same length. A span of 36 years contains eight or nine leap days depending on where it starts, so the total-days figure is computed by counting actual calendar days rather than multiplying by 365.
Can I calculate my age on a date in the past or future?
Yes. Change the “Age at” date to any date on or after the birth date. This is useful for forms that ask for your age on a specific date, such as an exam registration or an insurance start date.