# Seems like it should be simple? (need formula to adjust based on previous months input)

1. ## Seems like it should be simple? (need formula to adjust based on previous months input)

Hi!

But basically I have 12 months, and have 6000 to spread across those 12 months, as a sort of forecast.

But then I want to put in actuals each month as static values. I then want any remaining future months to calculate the spread of that 6000 but taking into account the actuals I've put in.

So in my example I put in 600 for Jan, and 100 for Feb. So then each remaining month should be calculated as 530.

Any help for a formula on this?

Thanks!

(I guess I'm asking: is there a way to do it without a helper row)?  Register To Reply

2. ## Re: Seems like it should be simple? (need formula to adjust based on previous months inpu

Leave A3 as is & use this in B3 & fill right
=(\$O\$2-SUM(\$A\$3:A\$3))/(12-COUNT(\$A\$3:A\$3))  Register To Reply

3. ## Re: Seems like it should be simple? (need formula to adjust based on previous months inpu

Thank you that works perfectly, but (and this might be kind of silly) what about at the start of the year when each month is a forecast? That formula won't work in January.  Register To Reply

4. ## Re: Seems like it should be simple? (need formula to adjust based on previous months inpu

You need to leave the Jan cell with your original formula.
With my solution starting in Feb  Register To Reply