A price calculation should distinguish a percentage payment fee from a fixed fee per transaction. Both can reduce the amount available after a sale. Use the actual payment provider’s terms rather than an assumed universal charge, and keep currency conversion or other costs separate when they apply.
Calculate from the selling price
A percentage fee is usually applied to a defined transaction amount under the provider’s terms. State the base used in your model. A fixed fee has a larger percentage effect on small transactions than on large ones.
Keep contribution different from net profit
Subtracting product cost and payment fees gives a useful intermediate figure, but it may still exclude support, overhead and other obligations. Label the result as a contribution estimate rather than guaranteed earnings.
Review the actual transaction record
Provider terms and settlement amounts can change. Reconcile the model with real receipts and update it when observed fees differ. Do not silently charge a customer a guessed surcharge without clear applicable terms.
A practical sequence
- Record the actual percentage and fixed fee basis.
- Apply both to a stated hypothetical or real selling price.
- Compare the estimate with actual settlement records.
An example
With a hypothetical $20 sale, $12 product cost, 3% fee and $1 fixed fee, the remaining contribution is $20 − $12 − $0.60 − $1 = $6.40 before other costs.
Questions about this topic
Is the example a stated Pro Max payment fee?
No. It is a hypothetical arithmetic example.
Does the remaining amount equal net profit?
No. Other expenses and obligations may still apply.
