Card Processing Fee Calculator
Enter what you process and what you currently pay. The calculator returns your real effective rate — the number that actually matters, not the headline one — then shows whether moving to interchange-plus would save money for your ticket size, not somebody else's.
| Line | Now | Interchange-plus |
|---|
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Why the headline rate is not your rate
A processor quoting “2.9% + 30¢” is not charging you 2.9%. They are charging 2.9% plus 30 cents on every single transaction. At a $5 ticket, that 30 cents alone is 6% of the sale, so your effective rate is 8.90%. At a $200 ticket the same fee is 0.15%, and your effective rate is 3.05%. Identical pricing, wildly different cost.
This is the first thing to fix in your own head, because every processor on earth quotes the number that looks smallest. The comparison only becomes honest once both sides are expressed as an effective rate on your actual volume.
The part most comparison sites leave out
Interchange-plus is the pricing model I would recommend to most merchants — but not to all of them, and the exception is arithmetic, not opinion.
Interchange-plus moves cost from a percentage to a fixed per-transaction fee. That is good when your tickets are large and bad when they are small. Below a certain average ticket, changing to interchange-plus costs you more than you save, even at a much lower headline rate.
On the defaults in this calculator, the break-even ticket is about $9. Below it, the “cheaper” interchange-plus quote is more expensive in absolute dollars. At a $5 ticket you pay $112 a month more in processing fees alone — $1,350 a year — against the $125 a month the same quote saves at a $100 ticket. The model doesn't have a direction; it has a threshold.
Every affiliate-funded comparison page has an incentive to skip this paragraph. The calculator above does not, because the number is computed from your inputs rather than asserted.
What interchange-plus does and does not fix
| Cost layer | Who sets it | Can you change it? |
|---|---|---|
| Interchange | The card networks, paid to the customer's bank | No |
| Assessments | Visa / Mastercard, roughly 0.14% | No |
| Processor markup | Your processor | Yes — this is the only negotiable line |
| Ancillary fees | Your processor | Yes, and often the largest win |
So the honest claim for interchange-plus is narrower than the sales pitch: it makes the negotiable part visible and it usually lowers the markup. It cannot lower interchange, and any provider claiming otherwise is either misinformed or moving the cost into a fee you have not looked at yet.
Reading the result
The monthly fee changes the answer more than the rate does
A $20 monthly fee needs roughly $3,600 of monthly volume to pay for itself at a 55-basis-point saving. A $99 monthly fee needs about $9,400. If you are below that volume, a low-markup provider with a monthly fee is worse than a slightly higher flat rate with none — and this is exactly the trade the calculator is showing you on the last line.
Why two merchants with the same processor pay different rates
Because card mix sets interchange, and you do not choose which card a customer pulls out. A rewards-heavy online mix can carry 40 basis points more interchange than a debit-heavy in-person mix, on identical pricing. That difference is not your processor's fault and not something you can negotiate away — but it does mean benchmarks you read online may not describe your business.
What this calculator does not model
Chargebacks, monthly minimums, PCI non-compliance penalties, early termination fees, and rate increases written into multi-year contracts. Those are frequently larger than the difference between two quotes, and they are all in the statement audit guide rather than in the arithmetic here.
Where the numbers come from
Interchange ranges and assessment rates are from the 2026 published US rate cards; flat rates are the published list prices of the large flat-rate processors. The calculator's defaults reflect a common online consumer card mix. Every rate in this tool is editable precisely because your mix is not the default — if the answer matters, put your own statement totals in.
Last reviewed 30 October 2026. Rates change twice a year, in April and October; if you are reading this much later, check the current published cards before relying on the defaults.