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Payment processing fee calculator
Enter the average order value, the number of orders and the processor's percentage, fixed and cross-border charges. The calculator returns the deduction per order, the effective rate, the monthly fee and the revenue left after processing.
This models percentage and fixed deductions only; chargebacks, refunds, reserves, monthly platform fees, currency spreads and taxes are separate and can change the effective rate.
The lines inside a card fee
Most card fees combine a percentage of the transaction with a fixed amount per authorisation. The percentage is often quoted as a single number, but it usually contains an interchange component paid to the issuing bank and a markup retained by the processor. The fixed amount covers authorisation and settlement and does not shrink with the ticket size.
Cross-border and currency conversion charges are separate. A sale in another currency may add a percentage for international acceptance and another for conversion into your settlement currency. Enter both only if the processor actually applies them to the orders you are modelling; otherwise leave them at zero to avoid double counting.
Why the effective rate differs from the headline
A 2.9% rate on a $29.99 order is about $0.87. Add a $0.30 fixed fee and the deduction is roughly $1.17, or 3.9% of the order. The smaller the ticket, the more the fixed fee lifts the effective rate; on a $5 order the same terms approach 9%.
The effective fee rate output divides the total deduction by order value, so it reflects both lines. Compare that number with the rate on your statement, not with the headline rate on a pricing page. Monthly fees and net monthly revenue then show what the terms cost at your actual order count.
What the calculator leaves out
Chargebacks, refunds, declined authorisations and reserve holds are not modelled. A refunded order may return part of the percentage but rarely the fixed fee, and a chargeback can add a flat penalty plus the lost sale. Those events can raise the real cost well above the calculated rate.
It also excludes monthly gateway or platform fees, statement fees, minimum monthly charges, tax on fees, and any negotiated interchange-plus arrangement. It does not decide which processor is cheaper for you, because published rates are starting points and negotiated quotes depend on volume, risk category and settlement currency. Use the output to compare like-for-like quotes, not as a final cost of acceptance.
Frequently asked questions
Why is the effective rate higher than the advertised percentage?
The fixed fee is charged per order and does not scale with order value. On small tickets it adds a larger percentage than it does on large ones, so the effective rate always exceeds the headline percentage.
Are processing fees refunded when an order is refunded?
Usually only part of the percentage is returned, and the fixed fee often stays. Policies differ by processor and contract, so check the statement rather than assuming a full reversal.
Does this include currency conversion?
Only if you enter a conversion percentage. The rate a processor applies may differ from the interbank rate and can include a spread, so use the all-in rate you actually see on settled orders.
Can I use this to compare processors?
Yes, if you enter each processor's all-in published terms and the same order profile. Quotes can include volume discounts, minimums and risk-based pricing that a single rate does not capture.
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