Age Calculator

Step 1: Enter your date of birth in the "Birth Date" field using the date picker or by typing directly. Select the year, month, and day.

Step 2: Optionally enter a target date in the "Target Date" field. If left blank, the calculator uses today's date. Use this to find your age on a specific past or future date — for example, your age on a future birthday or at a specific event.

Step 3: Click Calculate. The result shows your exact age in years, months, and days. The breakdown includes total days, total weeks, and total months for additional reference.

Calculating exact age is more nuanced than simply subtracting the birth year from the current year. A person born on November 15, 1990 is not automatically 35 years old on January 1, 2026 — they are still 35 until November 15, 2026, when they turn 36. The month and day matter.

The standard age convention used worldwide counts complete years since birth. You are considered a certain age from your birthday until the day before your next birthday. This is the "completed years" method — a 2-year-old has completed 2 full years of life.

Leap year birthdays create a special situation. Someone born on February 29 technically has a birthday only every 4 years. In practice, most legal systems and this calculator treat their birthday as March 1 in non-leap years. So a person born February 29, 2000 turns 26 on March 1, 2026 (not a leap year).

Age calculation in months and days follows calendar logic, not fixed-length months. From January 15 to February 15 is exactly 1 month, even though January has 31 days. From January 31 to February 28 is also considered 1 month (or 28 days). This matches how most people intuitively think about age — "I'm 5 months and 12 days old" follows the calendar, not a fixed 30.44-day month.

Total days and weeks are calculated using exact millisecond differences between dates, then dividing by 86,400,000 (milliseconds per day) and 7 (days per week). These values are always exact.

The calculator uses calendar-based subtraction to find exact age:

Step 1: Start with the year difference: Current Year − Birth Year

Step 2: Adjust for months. If the current month is before the birth month, subtract 1 year and add 12 to the month difference. If the current month equals the birth month, check the day.

Step 3: Adjust for days. If the current day is before the birth day, subtract 1 month and add the number of days in the previous month to the day difference.

Example: Born June 15, 1990. Today is March 20, 2026.
- Year difference: 2026 − 1990 = 36
- Month: March (3) < June (6), so subtract 1 year → 35 years
- Month difference: 3 + 12 − 6 = 9 months
- Day: 20 ≥ 15, so day difference = 20 − 15 = 5 days
- Result: 35 years, 9 months, 5 days

For total days: the exact millisecond difference between March 20, 2026 and June 15, 1990 divided by 86,400,000 = 13,062 days (approximately 1,866 weeks).

Example 1: How Old Am I?
Born August 25, 1995. Today is March 20, 2026. Enter your birth date and leave the target date blank. Result: 30 years, 6 months, 23 days. Total days: 11,164. Total weeks: 1,594.

Example 2: Age at a Future Event
Born March 10, 2005. A wedding is scheduled for June 15, 2027. Enter the birth date and June 15, 2027 as the target. Result: 22 years, 3 months, 5 days. You will be 22 at the wedding.

Example 3: Age Difference Between Two People
Person A born June 3, 1990. Person B born November 18, 1994. Calculate Person A's age using Person B's birthday as the target: 4 years, 5 months, 15 days apart.

Leave the target date blank for current age. The calculator defaults to today's date, giving you your exact age right now.

Use the target date for "age at" questions. How old will I be at graduation? On my wedding day? At retirement? Enter the future date to find out.

Total days is always exact. The years/months/days breakdown follows calendar conventions, but the total days count is a precise mathematical calculation with no rounding.

Age for legal purposes may differ. Some jurisdictions count age differently for voting, drinking age, or retirement eligibility. This calculator uses the standard international convention of counting completed years.

Leap year birthdays are handled. If you were born on February 29, the calculator correctly handles non-leap years by treating March 1 as the equivalent date.