Age Calculator

Enter the birth date, then choose the date on which the age should be calculated. The target date defaults to the browser's local calendar date, and Use today restores it whenever you have selected another date.

The main result shows completed calendar years, months, and days. It also shows total elapsed days and the next birthday date, weekday, and countdown.

Open the complete breakdown for total completed months and weeks, total days, date-equivalent hours, minutes and seconds, and the weekday of both entered dates.

Chronological age describes the calendar interval between a birth date and a target date. In the common birthday-based system, age increases after a complete birthday anniversary has been reached.

An exact result such as 26 years, 6 months, and 1 day means 26 complete birthday years, followed by 6 complete calendar months, followed by 1 remaining calendar day.

The word exact refers to the stated date-only calendar convention. It does not mean the calculator knows the person's birth time or the exact number of seconds lived.

The calculation first finds the latest completed birthday anniversary on or before the target date. That determines the completed years.

It then counts complete calendar months after that anniversary, respecting the actual length of each month. Any remaining interval becomes the day component.

This larger-units-first approach is more meaningful for calendar age than dividing the total number of days by 365 or by an average month length.

Total elapsed days is a continuous count of calendar-day boundaries between the two dates. Exact calendar age organizes the interval into years, months, and remaining days.

Years may contain 365 or 366 days, while months contain 28, 29, 30, or 31 days. For that reason, the same number of calendar months can represent different numbers of elapsed days.

Complete weeks are obtained from total elapsed days, while complete months come from the calendar-age breakdown. They answer different questions and should not be converted into one another using a fixed ratio.

The calculator finds the next occurrence of the birth month and day on or after the target date. If the target date is the birthday, the countdown is shown as Today.

The remaining-day count is based on civil calendar days rather than clock hours, so daylight-saving changes do not make a birthday appear one hour closer or farther away.

The result also shows the weekday and the age that will be reached on that birthday.

February 29 exists only in Gregorian leap years. In a common year, a calculator must choose another date when it needs a birthday anniversary.

This tool provides two explicit options: February 28 or March 1. The selected rule can affect the exact age and next-birthday countdown around the end of February.

There is no single setting that is legally correct for every purpose and jurisdiction. For example, some legislation explicitly specifies March 1, while another organisation or contract may apply a different rule.

Calendar months are not equal-length units, so a years–months–days interval can depend on how month-end anniversaries are handled.

This calculator clamps an anniversary to the final valid day when the corresponding day does not exist in the shorter month. For example, one month after January 31 is treated as February 28 in a common year.

Another calculator may use an end-of-month rule or a different borrowing method and produce a different month-and-day breakdown while still producing the same total elapsed days. The convention should therefore be stated rather than hidden.

A birth date is normally a civil calendar date, not a UTC timestamp. Converting date-only values through local midnight can shift a date or create a 23-hour or 25-hour day around daylight-saving transitions.

The calculation works directly with Gregorian year, month, and day values. It does not use local-midnight millisecond subtraction for calendar age or elapsed-day totals.

The selected target date is based on the browser's local date when Use today is pressed, but the arithmetic after selection is timezone-independent.

The tool multiplies total elapsed days by 24, 1,440, and 86,400 to produce date-equivalent hours, minutes, and seconds.

These totals are useful for understanding scale, but they do not include an exact time of birth, target time, historical timezone changes, daylight-saving transitions, or leap seconds.

A precise elapsed-time calculation requires two complete timestamps and clear timezone rules, not only two calendar dates.

The calculator is useful for checking current age, finding age on a past or future date, planning a birthday, comparing personal records, and expressing age in completed months or total days.

It can also support a preliminary check against an application or program cutoff date, but the official notice may define inclusion, attainment, leap-day handling, or age bands differently.

For legal, medical, educational, financial, employment, insurance, or government decisions, use the responsible organisation's rules and required documents.

The calculation runs in the browser. Birth and target dates are not sent to an external age-calculation service.

The calculator does not require a name, account, birth certificate, identity number, medical record, or uploaded document.

Avoid entering dates belonging to another person on a shared device when the visible result itself could reveal private information.