The fee for transactions on CP is calculated using formula provided by Stripe. It is based on their 2.9% + $0.30 transaction fee, plus the ClassroomParent $1.00 convenience fee.
In order to ensure that you get 100% of the price of the product, the fee ends up being a bit more than simply multiplying the total of the product price by 0.29 and adding $1.30. This is because Stripe charges their percentage on the entire order, which includes the additional amount charged to the purchaser to cover the fee.
Here is an example. Let’s say you had a $50 product that a purchaser wanted to buy 2 of, for a total of $100.
To get the correct fee, so that you get the full $100, we do the following calculation:
($100.00 + $0.30 + $1.00) / (1 - 0.029) = 104.33.
So the fee on a $100 purchase is $4.33, as Stripe will charge $3.33 in fees, plus the $1.00 convenience fee.