Date of Birth Calculation

use YOUR_DB

DECLARE @FromDate DATETIME = '1992-01-26 23:59:59.000',

        @ToDate   DATETIME = '2016-12-19 00:00:00.000',

        @Years INT, @Months INT, @Days INT, @tmpFromDate DATETIME

SET @Years = DATEDIFF(YEAR, @FromDate, @ToDate)

 - (CASE WHEN DATEADD(YEAR, DATEDIFF(YEAR, @FromDate, @ToDate),

          @FromDate) > @ToDate THEN 1 ELSE 0 END)

SET @tmpFromDate = DATEADD(YEAR, @Years , @FromDate)

SET @Months =  DATEDIFF(MONTH, @tmpFromDate, @ToDate)

 - (CASE WHEN DATEADD(MONTH,DATEDIFF(MONTH, @tmpFromDate, @ToDate),

          @tmpFromDate) > @ToDate THEN 1 ELSE 0 END)  

SET @tmpFromDate = DATEADD(MONTH, @Months , @tmpFromDate)

SET @Days =  DATEDIFF(DAY, @tmpFromDate, @ToDate)

 - (CASE WHEN DATEADD(DAY, DATEDIFF(DAY, @tmpFromDate, @ToDate),

          @tmpFromDate) > @ToDate THEN 1 ELSE 0 END) 

SELECT @FromDate FromDate, @ToDate ToDate,

       @Years Years,  @Months Months, @Days Days

Output : -