Age Calculator

The Age Calculator can determine the age or interval between two dates. The calculated age will be displayed in years, months, weeks, days, hours, minutes, and seconds.

Modify the values and click the calculate button to use

Date of Birth

Age at the Date of

Note: The age of a person can be counted differently in different cultures. This calculator is based on the most common age system where age increases on a person’s birthday.

In some situations, the months and day result may be confusing, especially when the starting date is the end of a month. For example, from Feb. 28 to Mar. 31 could be considered either as one month (counting both as month ends) or one month and 3 days (counting day-to-day). This calculator uses the day-to-day method.

Age can be calculated differently across cultures.
This calculator uses the most common age system, where your age increases on your birthday each year. For instance, someone who has lived for 3 years and 11 months is still considered 3 years old, and they will turn 4 on their next birthday, one month later. This method is widely used in most Western countries.

Other cultures use alternative age systems.
In some traditions, age is expressed by counting the current year of life. That means a person who is 20 years old might also be described as being in their 21st year. In a traditional Chinese system, a person is considered 1 year old at birth, and everyone’s age increases together at the Chinese New Year. For example, a baby born just one day before the Chinese New Year will be considered 2 years old just two days later, even though they are only 2 days old.

Sometimes, age calculations involving months and days can be tricky.
This usually happens when the starting date is at the end of a month. For example, we consider February 20 to March 20 to be one month. But from February 28, 2022 to March 31, 2022, there are two valid ways to calculate the age:

If you count February 28 to March 28 as one month, the result is 1 month and 3 days.
If you treat both February 28 and March 31 as end-of-month dates, the result is simply 1 month.

Both interpretations are valid, and similar issues arise with dates like April 30 to May 31 or May 30 to June 30. These inconsistencies are due to the varying lengths of months. For consistency, this calculator follows the first method.