Help with formula to calculate profit margin

[richiwatts]

What formula would I need to use to calculate profit margin here. I am getting confused when the VAT is included and not

A1 - Purchasing price (exl VAT) - 7.61
A2 - Selling price (inc. VAT) - 19.99
A3 - Commission paid on selling price incl vat - 15%
A4 - P&P (exl VAT) - 5.41

A5 - Profit = 4.36

A6 - Margin

If I am thinking correctly it would be (19.99/1.15) - 7.61 - 5.41 = 4.36

So what formula do I need for A5 and A6?

Thanks for your help

 

[csuanes]

Hi Richiwatts, from your formula (19.99/1.15) - 7.61 - 5.41 = 4.36 (is it based on A3? because this figure is 115%​)