Formula to Determine 2 Unknown Values to Achieve Minimum Product Gross Margin

[blawless]

Good Morning!
I am working with a list of products to be sold on Ebay. The Ebay seller fee is 10% of the selling price and I would like to price products so that the minimum Gross Margin is 12%. Can anyone help with formula(s) to obtain the minimum selling price?

The known fields are product cost, shipping cost, gross margin %. The 2 unknown values are the Price and the subsequent Ebay fee, which is 10% of the selling price.

Ebay Price Calculator.JPG

Thanks very much.
Bob

[MrShorty]

I find that I must first understand the math behind a problem before I can program a solution. Since I don't do this sort of calculation, I am a little shaky on the math. I also find that these tend to be mostly algebra problems. Check my algebra:

12%<=margin=(price-10%*price-shipping-cost)/price

If that is correct, then it should be as "simple" as solving that equation/inequality for price. I expect that it has been a while since secondary school and algebra classes, but can you solve that for price? If you need a refresher, this is a decent series of brief tutorials on solving linear algebra equations: http://www.purplemath.com/modules/solvelin3.htm

[blawless]

Thanks very much. Your math to calculate the margin is correct! I am unsure what formula is needed in the price column to achieve a 12% margin given the fee is 10% of the price. I will reference your link and investigate the this - Thank You.