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
About Age Calculation
Different cultures measure age in various ways. This calculator uses the most common system, where a person’s age increases on their birthday. For example, someone who has lived for 3 years and 11 months is considered 3 years old, turning 4 on their next birthday. This method is widely used in Western countries.
However, some cultures count age differently. In certain traditions, age is calculated by including or excluding the current year. For instance, a person who is 20 years old may also be referred to as being in their 21st year of life. In one traditional Chinese system, newborns start at age 1, and their age increases on the Lunar New Year rather than their birthday. So, a baby born a day before the Lunar New Year would turn 2 years old just days after birth, despite being only a few days old.
Additionally, calculating age in months and days can sometimes be confusing, particularly when dealing with varying month lengths. For example, counting from February 20 to March 20 is straightforward (one month). But from February 28 to March 31, there are two interpretations:
- Counting February 28 to March 28 as one month, leaving 3 extra days.
- Treating both dates as month-ends, making it exactly one month.