The equation
Gross per delivered order = Price − COGS − Shipping − Fees − Packing − Confirmation − Ads Return cost per delivered = Return cost × ReturnRate ÷ (1 − ReturnRate) Net profit per order = Gross − Return cost per delivered
Why divide by (1 − return rate): the cost of returns is carried by the successful order. At a 15% return rate, every 85 successful orders carry the cost of 15 returns — so the successful order's share is more than 15% of the cost, not equal to it.
The model's limits: per single order and variable costs only. Rent and fixed salaries are not included. It also assumes returned goods come back sellable — if not, raise the cost of a return.