Addative Percentages

Hi folks.

I'm currently working on a spreadsheet to give a target update for various partners I work with.
I need to work out a percentage value for a quater, which is dependant on the input of a percentage of retail target figure. So for instance I have:
Jan - 125% of retail target
Feb - 60%
March - 100%

I need to show a quater value, which I have come to the conclusion is:
(1-(((1-B8)+(1-B9)+(1-B10))/3)

Which just so happens to be the average value

Which works out as 95%
But if these percentage figures are derived from a actual/target like:
Jan - 4 target, 5 actual
Feb - 5 target, 3 actual
March - 6 target, 6 actual
Then my "true" percentage actual works out at 15 target, 14 actual which is 93.34%

Is there a better way to work out the quartile percentage?

That would depend on how your spreadsheet is set up. If you have a column with Target values (let's say col B) and a column with Actual (Col C) you can use

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Again, without knowing what data you have set up and how, it's impossible to give the formulas.

ChemistB

input of a percentage of retail target figure.

It's being input as a percentage, I could ask for the figure to be given as target/actual but if I can I want to avoid that if I can.

I tried to think of it as 125% of 100%, which resulted in the first formula.

Your formula is identical to finding the average (mathematically it simplifies). I think this works fine if the targets are identical month by month but will be off if they vary. As an extreme example, I did the following;

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where the formula is your formula (which matches Average). However if you sum actual first and divide by target, you do get a different number (extreme in this case).

ChemistB