Age Calculator

Calculate your exact age from your date of birth

This age calculator uses your date of birth to show your exact chronological age in years, months, and days. Choose today or another reference date to answer “How old am I?” for the date that matters to you. The results also include your age in total months, weeks, and days.

How to use the age calculator

1. Enter your complete date of birth.
2. Keep today as the reference date or select another date.
3. Select Calculate age to see your exact age and birthday details.

Using a past or future reference date makes this date of birth calculator useful for checking how old you were on an earlier date or how old you will be on a future date.

How your chronological age is calculated

Your chronological age is the calendar time between your birth date and the selected reference date. The calculator first counts complete years, then complete months, and finally the remaining days. It uses actual calendar dates, so leap years and months with different lengths are included in the calculation.

This calendar-based method is why an exact age can differ from a simple estimate made by subtracting birth years. If your birthday has not occurred yet in the reference year, that year is not counted as a complete year.

What your age calculation includes

• Your exact age in calendar years, months, and days
• Your approximate total age in months and complete weeks
• Your exact total number of days since your date of birth
• Your birth weekday, next birthday date, and days until your next birthday
• Your Western zodiac, Chinese zodiac, birthstones, and birth flowers

Birthday calculator and age in days

Beyond your age in completed years, this birthday calculator shows when your next birthday falls and how many days remain until it arrives. The age in days result counts the full elapsed period, which is helpful when years alone are not precise enough.

Can I calculate my age on another date?

Yes. Change the reference date to calculate your age on any valid date after your birth. You can use it for an application date, anniversary, school enrollment, historical milestone, or future birthday instead of calculating only your age today.

Who shares your birthday?

Discover notable people connected to your date of birth. Birthday matches are shown in three groups:

• Same birth date: the same year, month, and day as you
• Same birthday: the same month and day, regardless of birth year
• Same birth year: born in the same calendar year as you

Use the country filter to narrow the matches, and select Show more to browse additional people. When a Wikipedia link is available, select the person's name or birthday details to open their biography.

Matches are ordered by Historical Popularity Index (HPI), highest first. HPI is Pantheon's measure of historical popularity based on Wikipedia data, rather than a live popularity ranking or a judgment of someone's achievements. Select the question mark beside a score for a brief explanation.

The list includes entertainers, athletes, political figures, and historical personalities from the Pantheon dataset, with person details supplemented by Wikidata. It is not a complete list of everyone born on a date, so a missing match does not mean that no notable person shares your birthday.

References

1. Age definition — CDC/NCHS. Defines completed-year age using a birth date and a reference date.
2. Monthly birthstones — GIA. Source for the birthstones shown in the results.
3. Monthly birth flowers — The Old Farmer’s Almanac. Source for the birth flowers shown in the results.
4. Pantheon 2025 Person Dataset. Pantheon by Datawheel. Source of the person list and historical popularity scores used for birthday matches. We filter the dataset and supplement person details with Wikidata. Pantheon-derived data is available under CC BY-SA 4.0. Dataset citation: Yu, A. Z., et al. (2016), Pantheon 1.0, Scientific Data, 2:150075, doi:10.1038/sdata.2015.75.
5. Wikidata structured data. Source of supplementary person details for birthday matches, available under CC0.