Formula of age calculate using JavaScript

How to calculate date to date or date of birth using Javascript?

Learn the formula. Here are 2 JavaScript methods given below to calculate age or date to date.

Important: here is perfect formula of date calculate. nowadays, many websites and applications using this formula.

Best and accurate Age Calculate Formula in Javascript

Here, Birth Date Calculator in Javascript [formula 1, calculations method]


<script>
     
function calculateAge(birthDate) {
  const today = new Date();
  
  const ageInMilliseconds = today - birthDate;

  const years = Math.floor(ageInMilliseconds / (1000 * 60 * 60 * 24 * 365.2422));

const monthsInMilliseconds = ageInMilliseconds % (1000 * 60 * 60 * 24 * 365.2422);
  
  const months = Math.floor(monthsInMilliseconds / (1000 * 60 * 60 * 24 * 30.4368));

  const daysInMilliseconds = monthsInMilliseconds % (1000 * 60 * 60 * 24 * 30.4368);

  // Calculate the number of days in the remaining milliseconds.
  const days = Math.floor(daysInMilliseconds / (1000 * 60 * 60 * 24));

  return { years, months, days };
}

const birthDate = new Date("1996-06-03");
const age = calculateAge(birthDate);

alert("Your age : "+age.days+" days, "+age.months+" months, "+age.years+" years")


</script>

Here's a concise explanation of the code:

Function Breakdown:

calculateAge(birthDate):

Takes a birth date as input.

Calculates the age in years, months, and days.

Returns an object containing those values.

Steps:

Gets today's date

Calculates age in milliseconds (difference between today and birth date)

Divides milliseconds into:
- Years: using average days per year (365.2422)
- Months: using remaining milliseconds and average days per month (30.4368)
- Days: using remaining milliseconds

Returns an object with years, months, and days values

Example Usage:

Sets a birth date

Calls calculateAge to get the age

Displays the age in a message

Key Points:

Uses milliseconds for accurate time calculations.

Approximates years and months based on average days.

Returns a structured object for easy access to age components.

Birth Date Calculator in Javascript [formula 2 ,IF Method ]


   <script>
   today = new Date() ;
birth = new Date("1996-06-03");
  
years = today.getFullYear() - birth.getFullYear();
months= today.getMonth() - birth.getMonth();
days= today.getDate() - birth.getDate();
  
if(days<0){months-=1;days+=30;}

if(months<0){years-=1;months+=12;}

alert("IF formula "+days+":"+months+":"+years)
</script>

Here's a short explanation of the code:

1. Sets dates:

Stores today's date in a variable named today.

Creates a date object called birth for the date "1996-06-03".

2. Calculates age differences:

Subtracts the birth year from the current year to get years.

Subtracts the birth month from the current month to get months.

Subtracts the birth day from the current day to get days.

3. Adjusts for negative differences:

If days is negative (meaning the current day is before the birth day in the month), it subtracts 1 from months and adds 30 to days to account for the month boundary.

If months is negative (meaning the current month is before the birth month), it subtracts 1 from years and adds 12 to months to account for the year boundary.

4. Displays results:

Uses an alert box to display the calculated age in the format "days:months:years".

Key points:

The code calculates age based on full years, months, and days, not just total days alive.

It handles cases where the current day or month is before the birth day or month.

It uses the Date object and its methods for date manipulation.

Click here to explore our Age calculate tool Age calculator

Formula of age calculate using JavaScript

How to calculate date to date or date of birth using Javascript?

Best and accurate Age Calculate Formula in Javascript

Birth Date Calculator in Javascript [formula 2 ,IF Method ]

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