Age Calculator
Calculate exact age on a chosen date in years, months, and days. You can also compare two birth dates and view total months, weeks, days, hours, minutes, and other time-based estimates.
How exact age is calculated
Calendar age is not the same as dividing elapsed days by 365. The calculator first counts complete calendar years, then complete months, then the remaining days between the birth date and target date. This method accounts for months with different lengths and leap years.
For example, a person born on August 14, 2000 turns 26 on August 14, 2026. On August 7, 2026, that person's completed age is still 25 because the birthday has not yet occurred in the target year.
Age in total days and other units
Total-day results measure elapsed calendar days between the two selected dates. Hour, minute, and second figures are derived from that elapsed duration and are best treated as estimates when no birth time or time zone is supplied. Daylight-saving transitions and local time zones can affect precise clock-time comparisons.
Leap-day birthdays
For a February 29 birth date, the completed calendar age still advances once per year, but the observed birthday in a non-leap year may depend on local law or personal convention. Use the calculator for elapsed time, and check the relevant authority when an exact legal eligibility date matters.
Common uses
- Find age on a past or future date.
- Compare the age difference between two people.
- Check elapsed days since a birth date or other event.
- Plan age-based milestones or anniversaries.
- Verify a calculation before completing a form.
Calculator results are informational. Legal age rules can depend on jurisdiction, the exact event, and sometimes the time of birth.
Related calculators
Use the date calculator for any two dates, the time zone converter for international time comparisons, or the countdown calculator for time remaining until an event.