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 FileMaker Pro Custom Functions

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Age ( birthday; today; format )

Rate this function:  

  Average rating: 4.1  (39 votes)
  Discuss this Custom Function

Kevin Kurpe, Grasp Learning

This calculation determines a person's age based upon their birthday and a given date.

Sample Input:
Age (
GetAsDate ( "8/31/1948" ) ;
GetAsDate ( "1/19/2011" ) ; 4 )
Sample Output:
62 years
4 months
19 days

 Then copy & paste into FileMaker Advanced's Edit Custom Function window.

Click here to copy To Clip Manager if you have myFMbutler's Clip Manager installed


The function will calculate a persons age. The result of this function can be displayed in four different formats:

1: Years
2: Years and Days
3: Years, Months and Days.
4: Years ¶ Months ¶ Days


// Chris Moyer
// Bob Bowers

// Geoff Wells, DataIsland Software LLC

// Kevin Kurpe

Note: these functions are not guaranteed or supported by Please contact the individual developer with any questions or problems.

This is my Custom Function and I want to edit it


5 most recent comments | Show all 7 comments

This function returns incorrect results:

A person born on Jan 31, 1982 is 27 years old on Jan 31, 2009;
A year earlier, on Jan 31, 2008 the same person was 25 years old - TWO years younger.

Not to mention that on Mar 1, 2011 this person will be "29 years and 1 months, and -2 days" old.

comment, VR
August 22, 2010 3:59pm

When I copy and paste and attempt to save, it stops with an error. Also I don't understand the use of "<" and "≥" in the variable calculations, as they seem to be used on one side of an "=" calculation rather than in place of an "=" sign.

Fritz Mills, Chicago, IL
September 01, 2010 2:53pm

DO NOT USE THIS FUNCTION! It is very error prone. If you look at the code, it ONLY looks at the two years (birth year and current year) to calculate the age, not accounting for which month of the year or day of the month the birthday is or the current date. So if the current day of the year is earlier than the day of the year of the birthdate, the age will be off by 1 year. It has other errors, too. Someone spent a lot of time formatting this, but didn't give the logic much thought. Don't use it.

Gary Amstutz, Tulsa
January 02, 2011 7:10pm


Use the one at

I just tried it, and it calculates the age correctly. This one doesn't!

Gary Amstutz, Tulsa
January 02, 2011 7:15pm

I updated this custom function to address an error related to how I was calculating "leap years".

Thanks for the feedback Gary!

Kevin Kurpe, Tampa, FL
January 19, 2011 2:28pm

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