How do I calculate my credit card cost of acceptance?

Your credit card cost of acceptance is the average of all your credit card fees over the previous 1 or 12 months, at your choice, expressed as a percentage of the total transactions.

For example, if your business accepted 10 credit card transactions last month at $300 each, and your processing fee is 3.4% + $0.30, the cost of acceptance would be expressed as:

((300 * 0.034 + 0.3) * 10) / 3000 = 0.035

or 3.5%.

This is the highest rate you can surcharge credit card payments in the U.S.