Calculating your profit percentage

I am busy tutoring some students in accounting and yesterday we struggled to calculate the profit percentage. Usually they will either give you the selling price and the profit percentage so you can calculate the cost price. Or they will give you the cost price and the profit percentage so you can calculate the selling price.

But now they give you:

The total cost price of all the sales               R510 000

The total selling price of all the goods            R641 000

The total debtors allowance                         R29 000

And now you have to calculate the profit percentage...

Here is steps with formulas I worked out for this equation that will help:

Step 1: Selling Price - Cost Price - Debtors allowance = profit

Step 2:     profit        x    100

            Cost price            1

         

     =     profit percentage

Example:

Step 1: R641 000 - R510 000 - R29 000 = R102 000

Step 2: R102 000  x  100

           R510 000        1

       =    20%