Percentage Calculations

[sean fergusson]

Ok, I wasn't very good at maths so bear with me.

I need to calculate figures based on a percentage of the whole.

ie a+b+c+d+e=T

now the doozy, a is fixed b is fixed and everything else is a percentage of
T.

the calculation is to work out gross profit percentages so all the
percentages are tax, commisions and for the sake of the problem a 30% GPP
giving us a total Retail Price (T.) can excel equate these figure and if so
how? if any one can help please do as i am tooo young to have a heart attack
from stress. Thanks in advance for anyone who can help.....

--
Sean Fergusson

National Security Systems

--
Sean Fergusson

National Security Systems

Ph: 1300 556 469
Fax: 9300 1011

Mob: 0439 359 264

 

[Guest]

Hi Sean
Try putting your Total in Say F1
Then
A1 =fixed amount
B1= fixed amount
c1=F1*% so if C1 was 25%, it will be =F1*.25
D1=F1*%so if C1 was 10%it will be =F1*.10
E1=F1*%....etc,etc.

HTH
Michael

 

[Jay]

Ok, I wasn't very good at maths so bear with me.

Lot of that going around.

I need to calculate figures based on a percentage of the whole.

ie a+b+c+d+e=T

now the doozy, a is fixed b is fixed and everything else is a
percentage of T.

OK, suppose the specification is:
c is p percent of T
d is q percent of T
e is r percent of T

Put these constants in a spreadsheet:
p in C1
q in D1
r in E1
a in A2
b in B2

Put these formulas in a spreadsheet:

C2: =$F2*C$1/100
D2: =$F2*D$1/100
E2: =$F2*E$1/100
F2: =(A2+B2)/(1 - $C$1/100 - $D$1/100 - $E$1/100)

The total is in F2. The values c, d, and e are in C2, D2, and E2.

For more cases, you can copy row 2 and paste it into later rows.



Here's the math behind this.

The problem statement is:
T = a + b + p*T/100 + q*T/100 + r*T/100

Getting all the T stuff on the left:
T - p*T/100 - q*T/100 - r*T/100 = a + b

Solving for T:
T = (a + b)/(1 - p/100 - q/100 - r/100)