Dan,

No point in memoraizing a formula.

Simply understand the logic and you will never miss it:

If last year's sales = X,

Rate of increase or decrease = r%, and

This Year's revenue = 1000.

Then, 1000=X*(100%+r%) === note if r is to be mentioned with its symbol
i.e.ngeative for a decrease and positive for increase.

Therefore,

X = 1000/(100% + r%)

Please make sure while arrivng at r% that whether your this year's revenue
is grown by 51% over last year or grown by 151% over last year. If it ilater
case i.e. grown by 151% over last year then David is right.

Thanks,

Manish Bajpai

"David Billigmeier" wrote:

Dan -
It actually will work, just use like so:

<Current Year Sales = <Last Years Sales * (1+<percentage change)

So in your example, you had current year sales of 3700 and a decrease of
11.6%, so the formula would become (remember I said use a negative percentage
for decreases):
3700 = <Last Years Sales * (1+(-.116))
3700 = <Last Years Sales * (1-.116)
3700 = <Last Years Sales * .884
Last Years Sales = 3700/.884
Last Years Sales = 4185.52

If you are getting confused by Manish (when he says an increase in sales by
151% means multiplying by 1.51), he is wrong... look:

Once again use your information:

4500 = <Last Years Sales * (1 + 1.51)
4500 = <Last Years Sales * 2.51
Last Years Sales = 4500/2.51
Last Years Sales = 1792.83.

Hope this helps,
--
David Billigmeier


"Dan" wrote:

Hmm, this "general" formula doesn't seem to work for the negative
changes. Any other thoughts?