Important details about “ROI” and “ROI calculation”

There are two common ways to calculate your profit in the Amazon business – one is to consider the profit margin, and the other is to calculate Return on Investment. Now
Before Understanding ROI, first, understand PPU and Profit margin
PPU formula: Selling price – Total COG – Amazon fees
Example
Selling Price = 20 pounds
COG = 7 pound
Amazon fees = 3 pounds
VAT on Amazon Fees = 3 pounds
PPU = 20 _ 7 _ 3 _ 3 = 7 Pound
Just take the above example
Profit margin = 7 / 20 * 100 = 35%
Now let’s discuss ROI
When thinking about your Amazon ROI, it’s very important to factor in Amazon fees and the cost to ship your products to Amazon FBA warehouses. These expenses make a huge difference to the Amazon seller profit margin you are going to enjoy.
Example
For example, your product buying price is 7 pounds and your selling price is 20 pounds,
What will be your ROI?
ROI = PPU / COG + Amazon fees * 100
ROI = 7 / 7 + 3
7 / 10 * 100 = 70%
If you have any questions regarding this, Do ask in a comment.
Thanks