Calculate the exact age or interval between two dates. Results are displayed in years, months, weeks, days, hours, minutes, and seconds — with your next birthday countdown included.
Enter date of birth and target date
The Age Calculator determines the age or interval between two dates. It is based on the most common Western age system, where age increases on a person's birthday. This calculator expresses your age not only in years, but also in months, weeks, days, hours, minutes, and seconds — giving you a complete picture of how much time has passed since your birth.
For example, a person who has lived for 3 years and 11 months is considered 3 years old, and their age will become 4 on their next birthday.
Age is calculated by counting complete years from your date of birth to the target date, then counting remaining complete months, and finally the remaining days. The calculation accounts for varying month lengths (28–31 days) and leap years (February 29). When the starting date falls at the end of a month, the convention is that Feb 28 to Mar 28 equals one month, with any remaining days counted separately.
In some cultures, age is counted differently. In one traditional Chinese system, a person is born at age 1 and their age increases at the Chinese New Year rather than on their birthday. In the Korean age system, everyone is born at age 1 and gains a year on January 1st. This calculator uses the Western (international) age system, which is the most widely used globally.
Note: When the starting date is at the end of a month (e.g., Feb 28), the day calculation follows the convention that Feb 28 to Mar 28 equals one month, with any remaining days counted separately.
Frequently Asked Questions