What formulae do I use to get a percentage going back down.

[Guest]

If I have a figure to which I have to apply an additional 17.5% say $100 so
that it eqals $117.5. What formula do I use to work out what the original
starting price was when I am confronted by $117.50 ie I want to get back to
the $100 figure. So in this case 17.5% up is what formula to go down and
what is the rule for going down from an number.

Hope this clear and much thanks.

Eqa

 

[Rick Rothstein \(MVP - VB\)]

If I have a figure to which I have to apply an additional 17.5% say $100

so
that it eqals $117.5. What formula do I use to work out what the original
starting price was when I am confronted by $117.50 ie I want to get back
to
the $100 figure. So in this case 17.5% up is what formula to go down and
what is the rule for going down from an number.

If the original price is X and you want to get the price with 17.4% tacked
on, you multiply by 1.175. This comes from doing this...

X + 0.175 * X = 1.175 * X (factor out the common X term)

So, the formula to go up is New = (1 + PercentAsDecimal) *Old

Hence, to go the other way, divide the above by (1+PercentAsDecimal).
Thus...

Old = New / (1 + PercentAsDecimal)

Example, what was the original price if $117.50 represents a 17.5% markup...

Old = $117.50 / 1.175 = $100

Rick

 

[Guest]

you need to know that 17.5 percent WAS applied(ie 100*1.175),or know what the
original starting price was.You get back to your original starting price by
dividing by 1.175 or determine your original increase by(117.5-100)/100

 

[Roger Govier]

Hi

To Increase the figure from Net to Gross
=A1*(1+17.5%)
Going the other way, you just divide instead of multiply so to Decrease
from Gross back to Net
=A1/(1+17.5%)

If you put the 17.5% (or any other percentage) in a cell, say B1 then
it becomes
=A1/(1+B1)

 

[Guest]

Roger and all thanks for that.

But I realise I need to find out what the difference is in between the new
and the old price. So in this case I have $117.50 how do i get the $17.50 by
itself.


Eqa

 

[Roger Govier]

Hi

how do i get the $17.50 by itself.

Then
=A1-(A1/(1+B1))

 

[Guest]

thanks for that

Hi

Then
=A1-(A1/(1+B1))