Calculate Age Based on Date of Birth

How to calculate age (in years) based on Date of Birth and getDate()

There are issues with leap year/days and the following method, see the update below:

try this:

DECLARE @dob  datetime
SET @dob='1992-01-09 00:00:00'

SELECT DATEDIFF(hour,@dob,GETDATE())/8766.0 AS AgeYearsDecimal
    ,CONVERT(int,ROUND(DATEDIFF(hour,@dob,GETDATE())/8766.0,0)) AS AgeYearsIntRound
    ,DATEDIFF(hour,@dob,GETDATE())/8766 AS AgeYearsIntTrunc

OUTPUT:

AgeYearsDecimal                         AgeYearsIntRound AgeYearsIntTrunc
--------------------------------------- ---------------- ----------------
17.767054                               18               17

(1 row(s) affected)

UPDATE here are some more accurate methods:

BEST METHOD FOR YEARS IN INT

DECLARE @Now  datetime, @Dob datetime
SELECT   @Now='1990-05-05', @Dob='1980-05-05'  --results in 10
--SELECT @Now='1990-05-04', @Dob='1980-05-05'  --results in  9
--SELECT @Now='1989-05-06', @Dob='1980-05-05'  --results in  9
--SELECT @Now='1990-05-06', @Dob='1980-05-05'  --results in 10
--SELECT @Now='1990-12-06', @Dob='1980-05-05'  --results in 10
--SELECT @Now='1991-05-04', @Dob='1980-05-05'  --results in 10

SELECT
    (CONVERT(int,CONVERT(char(8),@Now,112))-CONVERT(char(8),@Dob,112))/10000 AS AgeIntYears

you can change the above 10000 to 10000.0 and get decimals, but it will not be as accurate as the method below.

BEST METHOD FOR YEARS IN DECIMAL

DECLARE @Now  datetime, @Dob datetime
SELECT   @Now='1990-05-05', @Dob='1980-05-05' --results in 10.000000000000
--SELECT @Now='1990-05-04', @Dob='1980-05-05' --results in  9.997260273973
--SELECT @Now='1989-05-06', @Dob='1980-05-05' --results in  9.002739726027
--SELECT @Now='1990-05-06', @Dob='1980-05-05' --results in 10.002739726027
--SELECT @Now='1990-12-06', @Dob='1980-05-05' --results in 10.589041095890
--SELECT @Now='1991-05-04', @Dob='1980-05-05' --results in 10.997260273973

SELECT 1.0* DateDiff(yy,@Dob,@Now) 
    +CASE 
         WHEN @Now >= DATEFROMPARTS(DATEPART(yyyy,@Now),DATEPART(m,@Dob),DATEPART(d,@Dob)) THEN  --birthday has happened for the @now year, so add some portion onto the year difference
           (  1.0   --force automatic conversions from int to decimal
              * DATEDIFF(day,DATEFROMPARTS(DATEPART(yyyy,@Now),DATEPART(m,@Dob),DATEPART(d,@Dob)),@Now) --number of days difference between the @Now year birthday and the @Now day
              / DATEDIFF(day,DATEFROMPARTS(DATEPART(yyyy,@Now),1,1),DATEFROMPARTS(DATEPART(yyyy,@Now)+1,1,1)) --number of days in the @Now year
           )
         ELSE  --birthday has not been reached for the last year, so remove some portion of the year difference
           -1 --remove this fractional difference onto the age
           * (  -1.0   --force automatic conversions from int to decimal
                * DATEDIFF(day,DATEFROMPARTS(DATEPART(yyyy,@Now),DATEPART(m,@Dob),DATEPART(d,@Dob)),@Now) --number of days difference between the @Now year birthday and the @Now day
                / DATEDIFF(day,DATEFROMPARTS(DATEPART(yyyy,@Now),1,1),DATEFROMPARTS(DATEPART(yyyy,@Now)+1,1,1)) --number of days in the @Now year
             )
     END AS AgeYearsDecimal

How do I calculate someone's age based on a DateTime type birthday?

An easy to understand and simple solution.

// Save today's date.
var today = DateTime.Today;

// Calculate the age.
var age = today.Year - birthdate.Year;

// Go back to the year in which the person was born in case of a leap year
if (birthdate.Date > today.AddYears(-age)) age--;

However, this assumes you are looking for the western idea of the age and not using East Asian reckoning.

Calculate age based on date of birth

PHP ^{>= 5.3.0}

# object oriented
$from = new DateTime('1970-02-01');
$to   = new DateTime('today');
echo $from->diff($to)->y;

# procedural
echo date_diff(date_create('1970-02-01'), date_create('today'))->y;

demo

^{functions: date_create(), date_diff()}

---

MySQL ^{>= 5.0.0}

SELECT TIMESTAMPDIFF(YEAR, '1970-02-01', CURDATE()) AS age

demo

^{functions: TIMESTAMPDIFF(), CURDATE()}

How to calculate age based on date of birth in mysql?

You can use TIMESTAMPDIFF.

select TIMESTAMPDIFF(YEAR, str_to_date(dob, '%Y-%M-%d'), current_date) AS age
from user;

Calculate age given the birth date in the format YYYYMMDD

I would go for readability:

function _calculateAge(birthday) { // birthday is a date
    var ageDifMs = Date.now() - birthday.getTime();
    var ageDate = new Date(ageDifMs); // miliseconds from epoch
    return Math.abs(ageDate.getUTCFullYear() - 1970);
}

Disclaimer: This also has precision issues, so this cannot be completely trusted either. It can be off by a few hours, on some years, or during daylight saving (depending on timezone).

Instead I would recommend using a library for this, if precision is very important. Also @Naveens post, is probably the most accurate, as it doesn't rely on the time of day.

---

How do I calculate someone's age in Java?

JDK 8 makes this easy and elegant:

public class AgeCalculator {

    public static int calculateAge(LocalDate birthDate, LocalDate currentDate) {
        if ((birthDate != null) && (currentDate != null)) {
            return Period.between(birthDate, currentDate).getYears();
        } else {
            return 0;
        }
    }
}

A JUnit test to demonstrate its use:

public class AgeCalculatorTest {

    @Test
    public void testCalculateAge_Success() {
        // setup
        LocalDate birthDate = LocalDate.of(1961, 5, 17);
        // exercise
        int actual = AgeCalculator.calculateAge(birthDate, LocalDate.of(2016, 7, 12));
        // assert
        Assert.assertEquals(55, actual);
    }
}

Everyone should be using JDK 8 by now. All earlier versions have passed the end of their support lives.

How to calculate age in years and months based on date of birth in Microsoft CRM 2011

you can try below code if DOB is in format "MM/dd/yyyy". You can also change it for other formats accordingly.

var now = new Date(); //Todays Date   
var birthday = Xrm.Page.getAttribute("birthdate").getValue();
birthday=birthday.split("/");   

var dobMonth= birthday[0]; 
var dobDay= birthday[1];
var dobYear= birthday[2];

var nowDay= now.getDate();
var nowMonth = now.getMonth() + 1;  //jan = 0 so month + 1
var nowYear= now.getFullYear();

var ageyear = nowYear - dobYear;
var agemonth = nowMonth - dobMonth;
var ageday = nowDay- dobDay;
if (agemonth <= 0) {
       ageyear--;
       agemonth = (12 + agemonth);
        }
if (nowDay < dobDay) {
      agemonth--;
      ageday = 30 + ageday;
      }
var val = ageyear + "-" + agemonth + "-" + ageday;
return val;

you can also use some of below:

Simple age calculator in JavaScript

Calculate age in JavaScript

javascript - Age calculation

How can I calculate the number of years betwen two dates?

Oracle Age calculation from Date of birth and Today

SQL> select trunc(months_between(sysdate,dob)/12) year,
  2         trunc(mod(months_between(sysdate,dob),12)) month,
  3         trunc(sysdate-add_months(dob,trunc(months_between(sysdate,dob)/12)*12+trunc(mod(months_between(sysdate,dob),12)))) day
  4  from (Select to_date('15122000','DDMMYYYY') dob from dual);

      YEAR      MONTH        DAY
---------- ---------- ----------
         9          5         26

SQL>

---

Related Topics