Rolling 12 week calculations?!?!?

[ShellyB37]

Good afternoon everyone,

Wondering if I could obtain a little help with my little calculation problem

I have attached a sample workbook, using 14 weeks of info but eventually I will have 52 weeks + of info but only want the last 12 weeks in the calculations!!
I tried using a =SUMPRODUCT but because there was something wrong with the sum it wouldn't work & I erased it!!!

I need to be able to calculate the average amount of wages from the previous 12 weeks only, so eventually I will have 2 years worth of information but I only need it to calculate the previous 12 weeks each time I enter the current weeks value. I have tried suggestions from various sites but although the formula is fine, it is giving me a nil value which is wrong, so obviously I'm doing something wrong, I just don't know what & it is giving me a headache :'(

Many Thanks

[brokenbiscuits]

Welcome to the forum!

First of all, you need to change the title of your thread to something more search-friendly, or the mods will come down on you like a ton of bricks (it's Rule #1 in the Forum Rules)

Secondly, what formula are you using? Or better still, could you post a sample workbook? (click 'Go Advanced' then attach with the paper clip symbol.)

[ShellyB37]

Hi Everyone,

I thought I had found all the answers to my prayers yesterday, I found a formula & it worked but it seemed to have an effect on the rest of my workbook (i had tacked it on the end of my holiday entitlement workbook) so I removed it, thinking it's ok i have the formula, I will just start a new book solely for this purpose, unfortunately when I put the formula in, it wouldn't work & I can't understand why.

The formula i used was =AVERAGE(offset(F6,,count(F6:BV6)-12,,12))

i cannot understand why it was working & now it's not

Any help would be much appreciated

[ShellyB37]

I did try a second formula but that doesn't do what i want it to either, I am hoping that I am attaching my workbook so you can see what i am trying to achieve :S

[ShellyB37]

hopefully here is the workbook in it's entirety thus far

[ShellyB37]

It's sheet 7 thats giving me problems!!