Date

[dre0954]

I want to calculate someone's age using their DOB and current time and date. 

=(YEAR(NOW())-YEAR(C150)) this formula does not take into account the current time or day. 

23/11/2013 is returning age 6 now, it should return 5 now.

[#2]

@dre0954 

You can use the undocumented DATEDIF function to calculate age in years/months etc. To display just age in years, you could use:

=DATEDIF(A1,TODAY(),"y")

To display the age in years, months and days, you could use something like:

=IF(DATEDIF(A1,TODAY(),"y")<>0,DATEDIF(A1,TODAY(),"y")&" years ","")&IF(DATEDIF(A1,TODAY(),"ym")<>0,DATEDIF(A1,TODAY(),"ym")&" months ","")&IF(DATEDIF(A1,TODAY(),"md")<>0,DATEDIF(A1,TODAY(),"md")&" days","")

 Hope that helped.

[#3]

@dre0954 

By the way, DATEDIF() is documented - https://support.office.com/en-us/article/datedif-function-25dba1a4-2812-480b-84dd-8b32a451b35c

Another way is

=YEARFRAC(A1,TODAY(),3)

and INT() it if only full years are required

[#4]

I know that. What I meant was that it is undocumented inside the application.