Calculating average ages

[boxersrfun]

I need to find the average age of a group of people, by years and months.
For example if I need the average age of for these birthdays (3/19/90,
2/10/92, 12/3/89 and 1/12/90. I need an result like 17 years and 9 months.
Not just the average year.

I determined the number of days old each person was and then averaged the
days and divided by 365 and came up with 17.98013699. Is 17 yrs 9 months an
accurate interpretation? Is there an easier way to calculate?

Thanks for your help.

 

[pallaver]

Not sure where you're getting the 9 months from, but it's .98*** of
365 days, or 357 days, which most definitely falls in December, or 12
months.

I don't know if there's an easier way to calculate, do most of my work
in VBA, not on spreadsheets. Good luck, I'll visit this again to see
if somebody smarter than me posted the answer.

-np

 

[T. Valko]

17.98013699

Is 17 yrs 9 months an accurate interpretation?

I don't think so.....

Based on your use of a 365 day year, 98% of a year puts you at day 357.7
which is well into month 12.

Here's my thinking....

Get the average birthdate then calculate from there based on today's date.

A1 = 3/19/1990
A2 = 2/10/1992
A3 = 12/3/1989
A4 = 1/12/1990

All one one line:

=DATEDIF(AVERAGE(A1:A4),TODAY(),"y")&"yrs "
&DATEDIF(AVERAGE(A1:A4),TODAY(),"ym")&"m(s)"

Result = 17yrs 11m(s)

The average birthdate is 7/27/1990 so on 7/27/2008 the result would be 18yrs
0m(s).

 

[Jarek Kujawa]

=AVERAGE(TODAY()-A1:A4)

aray entered (CTRL+SHIFT+FORMULA), formatted as "yy-mm-dd"

results with "17-12-19" as today

on 7/27/2008 it will result with "17-12-30"

hope this makes sense

 

[David Biddulph]

The problem with that is that it is incapable of giving a zero for the
number of months or the number of days.

DATEDIF is a much better bet.

 

[Jarek Kujawa]

right
thks

 

[Gary''s Student]

Actually 11 months. With your data in A1 thru A4, in A5 enter:

=SUM(A1:A4)/4 displays: 7/27/1990

In another cell:

=DATEDIF(A5,TODAY(),"y")&" years "& DATEDIF(A5,TODAY(),"ym")&" months "

displays:

17 years 11 months