Formula needed for adding every nth column on another sheet

J

JJ

Hi

I have tried everything I can think of but with no luck - can somebody

On sheet 2 I have all the data in columns from rows 1-20.

On sheet 1 I want the total of the sums of every 3rd column.

ie. Sheet 1: A1 = sum Sheet 2: A1:A20
Sheet 1: B1 = sum Sheet 2: D120
Sheet 1: C1 = sum Sheet 2: G1:G20 and so on...

Instead of manually entering all the formulas on Sheet 1 for the sum totals
of every 3rd column, is there a formula I can enter in A1 on Sheet 1 and copy
across the row?

Thanks for any help!!

R

RagDyer

Try this:

=SUM(INDEX(Sheet2!\$A1:\$AB20,1,COLUMNS(\$A:A)*3-2):INDEX(Sheet2!\$A1:\$AB20,20,COLUMNS(\$A:A)*3-2))

You can enter this *anywhere*, and copy across as needed, though I've only
sized this out to Column AB!

J

JJ

Thanks RagDyer, it worked a treat!! I would never have got that myself.

T

Teethless mama

Shorter version:

=SUM(INDEX(Sheet2!\$1:\$20,,COLUMNS(\$A:A)*3-2))

R

RagDyeR

Nice!

I've noticed that you DO have a fine comprehension of that Index()
function!<g>

R

RagDyeR

You're welcome, and appreciate the feed-back, but do check out Tm's shorter
formula.

B

Bob Umlas

Sheet1!A1:
=SUM(OFFSET(Sheet2!\$A\$1,0,(COLUMN()-1)*3,20,1)) and fill right

Bob Umlas
Excel MVP