How to calculate age from Date of Birth in Java – 3 easy way

In this tutorial, We will learn how to calculate age from Date of Birth in Java. We will ask the user to enter their date of birth and from DOB, we will calculate their age also.

How to calculate age from Date of Birth in Java?

We can calculate age from Date of Birth by using the following methods:

1. Calculate age by using Period class.
2. Calculate age by using Calender class.

1. Calculate age by using Period class

We can calculate the age of the user by using the java.time.Period class.

What is java.time.Period class in Java?

The Period class forms a quantity or amount of time in the terms of years, months, and days in the ISO-8601 calendar system such as 26 years, 8 months, and 5 days. Period-supported units are YEARS, MONTHS, and DAYS. These fields are always present and may be set to zero also.

Syntax:

public final class Period
extends Object
implements ChronoPeriod, SerializableCode language: Java (java)

Let’s see the complete program to calculate age from date of birth by using the Period class.

package com.cf.latest;

import java.time.LocalDate;
import java.time.Period;
import java.util.Scanner;

public class CalculateAgeByUsingPeriod {

	public static void main(String[] args) throws Exception {
		String userGivenDate;

		Scanner sc = new Scanner(System.in);
		// Ask user to enter DOB
		System.out.print("Enter your DOB in YYYY-MM-DD format: ");
		userGivenDate = sc.nextLine();

		// Convert user given Date to Date format
		LocalDate dob = LocalDate.parse(userGivenDate);
		// Find current Date
		LocalDate currDate = LocalDate.now();

		// Calculate difference between DOB and current Date
		Period period = Period.between(currDate, dob);

		// Convert Period to Years, Months and Days
		int dobYear = Math.abs(period.getYears());
		int dobMon = Math.abs(period.getMonths());
		int dobDays = Math.abs(period.getDays());

		// Display user's age
		System.out.print("You age is " + dobYear + " years " + dobMon + " months " + dobDays + " days");

		sc.close();
	}

}
Code language: JavaScript (javascript)

Output:

Enter your DOB in YYYY-MM-DD format: 1996-12-05
You age is 25 years 9 months 30 days

2. Calculate age by using Calender class

We can calculate the age of the user by using java.util.Calendar class.

What is java.util.Calendar class in Java?

The Calendar class is the abstract class that provides methods for conversion between the specific instant of time and the set of Calendar fields like YEAR, MONTH, DAY_OF_MONTH, HOUR, and more, and for getting customizing calendar fields like getting the date of the next week or last week.

Syntax:

public abstract class Calendar
extends Object
implements Serializable, Cloneable, Comparable<Calendar>Code language: PHP (php)

Let’s see the complete program to calculate age from date of birth by using the Calendar class.

package com.cf.latest;

import java.util.Calendar;
import java.util.GregorianCalendar;

public class CalculateAgeByUsingCalendar {
	public static void main(String[] args) {
		// Accept DOB as parameter and form Calendar object
		Calendar calDOB = new GregorianCalendar(1987, 11, 9);

		// Get the current date
		Calendar currDate = new GregorianCalendar();

		// Find the age of the user
		int currAge = currDate.get(Calendar.YEAR) - calDOB.get(Calendar.YEAR);

		// Check and confirm current age
		if ((calDOB.get(Calendar.MONTH) > currDate.get(Calendar.MONTH))
				|| (calDOB.get(Calendar.MONTH) == currDate.get(Calendar.MONTH)
						&& calDOB.get(Calendar.DAY_OF_MONTH) > currDate.get(Calendar.DAY_OF_MONTH))) {
			// decrease age by 1
			currAge--;
		}
		// Display the age of the given user
		System.out.println("Your age is " + currAge + " years");
	}

}
Code language: JavaScript (javascript)

Output:

Your age is 34 years

Conclusion

In this tutorial, we have learned how to calculate age from Date of Birth in Java.

We have seen 2 different methods to accept the Date of Birth from the User and calculate the age by using both Period and Calendar classes. You can use any of the above methods to calculate age.

We hope, you can be able to achieve your requirement and like our tutorial. If our tutorial helped you or if you liked our tutorial, then please share it with others.

Thanks & Happy Learning!

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Other Queries We have Covered

• How to accept the date of birth from the user and calculate age in java?
• How to calculate the age of the user in Java?
• What is java.time.Period class in Java?
• What is java.util.Calendar class in Java?

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