Know what you really keep. Enter a transaction amount and your processor and this shows the fee and your net payout — so a price isn't quietly eaten by processing costs.
What this free tool is great for: a quick, one-off job with no signup — it runs in your browser and there's nothing to manage.
Its honest limit: you can compare up to three scenarios during this visit, but they are not kept after you leave, they won't update as your real numbers change, and this tool does not connect to your live accounts.
A free tool is fine for a one-off. If payment fee calculator is a weekly job, these take it off your plate.
Best for WordPress site owners taking payments in forms
Sounds like you? “Our order and booking forms need branching questions and online payments, and I want them running on my own site.”
Plan that fits: Pro, $159 a year for 3 sites; the Stripe, PayPal Checkout, Square and Mollie add-ons start at this tier
Best for Shopify stores with mixed payment and shipping options
Sounds like you? “Shoppers pick a payment or shipping method that doesn't suit their order, and we sort out the mess afterwards.”
Plan that fits: Starter, $6.99 a month or $58.70 a year, with 3 active rules in total.
Best for creators selling courses and memberships
Sounds like you? “My courses, events and member payments sit in separate tools, and none of them looks like my brand.”
Plan that fits: Professional, $89 a month billed yearly ($129 monthly); Circle also keeps a small cut of each sale
Best for new Shopify stores that look unproven
Sounds like you? “Shoppers hesitate at the buy button because they cannot see which payments we accept or what we promise.”
Plan that fits: Free plan; Starter at $6.99 a month lifts the one-block limit
Picked from our review dossiers: who each tool suits, their problem in their words, and the plan that fits. “Try” buttons are affiliate links: we may earn a commission if you sign up, at no extra cost to you. It never changes our verdict.
Every time a customer pays you by card or through an online processor, a slice of that money never reaches you — it goes to the payment processor as a fee. Individually the fees look tiny, a couple of percent here, a fixed few cents there. In aggregate, across thousands of transactions, they become one of the largest line items a business barely notices. This calculator shows you exactly what a given sale nets you after fees, and what a year of them adds up to — because the first step to controlling a cost is seeing its true size, and payment fees are experts at hiding in plain sight.
Most payment fees have two parts: a percentage of the transaction plus a small fixed amount. That structure is deliberate and it matters, because the two parts behave very differently as your transaction size changes. The percentage scales with the sale — a big order pays a big percentage fee. The fixed part doesn't move, which means on a small transaction it can dwarf the percentage. Knowing your fee is "X% plus Y fixed" rather than just "X%" is essential, because the blended rate you actually pay depends heavily on your typical order value, and the headline percentage tells only half the story.
The fixed portion of a fee is brutal on low-value sales. A fixed charge that's trivial on a large order can swallow a huge share of a small one — on a very small transaction, the fixed fee alone can be a double-digit percentage of the sale before the percentage part is even added. This is why businesses selling cheap items, running micro-transactions, or accepting tiny donations feel payment fees far more acutely than those with high order values.
If your average sale is small, minimising the number of separate transactions — through bundling, minimum order values, or subscriptions — can matter more to your margin than shaving the percentage rate.
Not all processors charge the same, and the differences add up. Rates vary by processor, by card type (premium rewards cards often cost merchants more), by whether the card is present or entered online, and by your business's size and risk profile. The convenient, easy-to-integrate processors often charge a simple flat rate that's higher than what interchange-plus pricing would cost a larger merchant. There's usually a trade-off between simplicity and cost: the lowest-fee option often demands more setup and volume.
Knowing your real blended rate — total fees divided by total sales — lets you judge whether you've outgrown your current processor's convenience premium.
The fees that surprise people most are the international ones. Accepting a payment in another currency, or paying out to another country, often triggers a currency-conversion fee plus a cross-border surcharge — and the exchange rate used may itself carry a hidden markup on top of the mid-market rate. Stack these together and an international transaction can cost several times what a domestic one does. For any business selling globally or paying overseas suppliers and contractors, these cross-border costs deserve as much scrutiny as the headline processing rate, because they're where a surprising amount of money silently leaks out.
Beyond the per-transaction fee sit costs that don't show up on every sale but hit hard when they do. Chargebacks — when a customer disputes a payment — often carry a fee on top of the lost sale, and too many can jeopardise your account. Refunds may not return the original processing fee. Monthly account fees, minimum charges, PCI-compliance fees and gateway fees all quietly add to the total. When you compare processors, the per-transaction rate is just the headline; the true cost includes this long tail of ancillary charges, which is where a cheap-looking headline rate can turn out to be the expensive option.
A tempting response is to add a surcharge so the customer covers the fee. Whether you can — and how — depends heavily on where you operate and the card network rules, which restrict or ban surcharging in various places and cap what you can add where it's allowed. Even where it's legal, it can dent conversion and goodwill, since customers dislike a fee appearing at checkout. Many businesses instead quietly bake the cost into their prices, spreading it across all sales rather than spotlighting it.
There's no universally right answer, but it's a decision to make deliberately, with the rules in mind, rather than assuming you can simply tack the fee on.
Once you can see the cost, several levers help. Raise your average order value so the fixed fee is a smaller share. Choose a processor whose pricing model fits your volume and order size rather than defaulting to the easiest one. Reduce chargebacks with clear billing descriptors and good customer service. For international money, use providers built for cross-border payments rather than paying general processors' hefty conversion markups. None of these is a silver bullet, but together they can meaningfully lift the share of each sale you actually keep — which, on thin margins, goes straight to the bottom line.
Around 2.9% + a fixed fee per transaction for cards (Stripe, Square), and ~3.49% + fixed for PayPal. International and currency conversion add more.
Negotiate rates at volume, pass small fixed fees into pricing, and for cross-border payments use a service like Payoneer with lower conversion costs.
No — it calculates the processor's percentage and fixed fee. Conversion markups on international payments are extra, and often the bigger cost.
The pricing behind our reviews is published as an open dataset, with the sentence behind every cost-trap flag and the date it was researched. Free to use with attribution (CC BY 4.0).
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