Payment fee & surcharge calculator

Almost every card processor charges the same two-part fee: a percentage of the transaction plus a fixed per-transaction fee. Stripe's standard US online rate is 2.9% + $0.30, PayPal's is commonly 3.49% + $0.49, and Square's online rate is around 2.6% + $0.10. The percentage scales with the sale, but the fixed fee is flat no matter how small the charge — and that combination is the single most misunderstood thing about card fees. On a $1,000 sale, Stripe's $0.30 fixed fee is a rounding error and your effective rate is barely above 2.9%. On a $5 sale, that same $0.30 is 6% on its own, pushing your effective rate to nearly 9%. The Stripe fee calculator mode above makes this visible: enter any charge amount and it shows the gross, the fee, the net you keep, and the true effective percentage for that specific amount.

Knowing the effective rate — not just the headline rate — changes how you price. If you sell low-ticket items, the fixed fee quietly eats a big chunk of every sale, which is a strong argument for bundling products, setting a minimum order value, or steering small purchases toward a payment method with a lower fixed fee. Conversely, if your average order is large, the percentage dominates and shaving even 0.2% off your rate (by negotiating, or by qualifying for a lower interchange tier) is worth real money at volume. The calculator lets you plug in your own numbers rather than the presets, so you can model the exact rate your processor gives you — including blended rates, interchange-plus pricing, or the higher rates that apply to international cards and currency conversion.

One of the most useful things this tool does is run the fee math backwards. Freelancers and small businesses constantly need to answer a question like "how much do I charge to receive $500?" — you have a number you need to actually land in your bank account, and you want the invoice total that nets out to it after the processor takes its cut. Guessing is surprisingly easy to get wrong, because you cannot simply add the percentage back on: adding 2.9% to $500 gives $514.50, but the fee is charged on the higher gross amount, so you would still come up short.

The correct formula is gross = (net + fixed) ÷ (1 − rate). To receive $500 net through Stripe at 2.9% + $0.30, you need to charge (500 + 0.30) ÷ (1 − 0.029) = $515.24 — and the tool computes this instantly in the "What to charge" mode. Enter the amount you want to receive, and it returns the exact figure to bill your customer, the fee that will be taken out, and the effective rate on that gross. This is exactly what you want when writing an invoice, quoting a price that must clear a specific margin, or passing the cost of the fee on to the buyer so that your take-home is protected. It pairs naturally with the invoice generator: work out the gross here, then drop it straight into the invoice.

The three preset processors cover most small-business and freelancer payment volume, and the differences between them matter more on small transactions than large ones. Stripe at 2.9% + $0.30 is the default for online businesses and SaaS, with clean APIs and predictable pricing. PayPal at 3.49% + $0.49 for goods-and-services payments is the most expensive of the three on both the percentage and the fixed fee, which is the trade-off for its enormous consumer reach and buyer trust — for a $20 sale, PayPal keeps noticeably more than Stripe. Square at 2.6% + $0.10 online has the lowest fixed fee of the three, which makes it comparatively attractive for lower-ticket items, and its in-person card-present rate is different again.

Because the presets are only a starting point, the calculator lets you edit both numbers after clicking a chip. That matters because published rates are rarely the whole story. Your real rate can be higher for American Express, for international cards, for manually keyed transactions, or for currency conversion; and it can be lower if you are on a negotiated or interchange-plus plan at volume. Rather than trusting a headline number, put your actual effective rate into the tool — you can usually find it by dividing the total fees on a recent payout by the total volume — and you will get numbers that match what actually hits your account. Selecting "Custom" clears the preset so you can enter any percentage and fixed fee from scratch.

A surcharge is an extra fee added to a transaction specifically because the customer is paying with a credit card — a way for a merchant to pass the processing cost on to the buyer rather than absorbing it. The question "is surcharging legal in my state?" does not have a single national answer, which is exactly why the "Surcharge check" mode exists. Surcharging is regulated at two levels that stack on top of each other: state law and card-network rules. You have to satisfy both.

At the state level, a handful of states restrict or prohibit credit card surcharges on consumer transactions. As of the 2026 estimate the tool ships with, surcharging is effectively banned in Connecticut, Massachusetts, Maine and Oklahoma, and Colorado allows a surcharge but caps it at 2% (or the actual processing cost, whichever is less). Most other states allow surcharging, subject to the network rules below. Pick your state from the dropdown and the tool shows a color-coded card — green for allowed, amber for capped, red for banned — with a short plain-English summary of the rule. It is worth noting that the legal landscape here shifts frequently as states pass, amend, or have courts strike down surcharge laws, so the map is a starting point for a conversation with your own advisor, not a compliance ruling.

At the card-network level, Visa and Mastercard impose their own requirements everywhere, regardless of state law. A credit card surcharge is capped (commonly up to around 3–4%, and never more than your actual cost of acceptance); you must register your intent to surcharge with the networks in advance; you must disclose the surcharge clearly at the point of entry and on the receipt; and you generally cannot surcharge debit or prepaid cards at all, even when they are run as credit. The tool surfaces this network layer alongside every state result, because "my state allows it" is never the whole answer.

Merchants trying to offset processing costs run into three related-but-distinct approaches, and mixing them up creates compliance risk. A surcharge is an added fee on credit card payments specifically — it is the most tightly regulated option, governed by the state and network rules above. A cash discount flips the framing: you post the higher (card) price as your standard price and offer a discount to anyone paying with cash. Because it is structured as a discount rather than a penalty, a properly implemented cash discount avoids most surcharge restrictions and is often the cleaner path where surcharging is banned — though the prices you display must genuinely reflect the program. A convenience fee is a flat fee for using an alternative payment channel (for example, paying an invoice online instead of by mail), allowed only in specific circumstances and generally not on your standard, customary payment method.

This tool focuses on the surcharge question because that is the one with a clear state-by-state legal map, but the practical takeaway applies to all three: whatever mechanism you use to pass on card costs, get the implementation reviewed before you turn it on. The rules govern not just whether you can add a fee but exactly how you must present it, and the penalties for getting disclosure wrong can exceed the fees you were trying to recover in the first place.

• Freelancers & consultants figuring out what to invoice so a specific amount lands after fees, and whether to pass the fee on to the client.
• Online sellers & e-commerce owners pricing products with the true effective rate in mind, especially for low-ticket items where the fixed fee bites.
• SaaS & subscription businesses modeling net revenue per plan across Stripe, PayPal and Square.
• Service businesses deciding whether — and where — a credit card surcharge or cash discount is legal and worth implementing.
• Bookkeepers & finance teams reconciling payouts and explaining the gap between gross sales and deposited amounts.
• Anyone sending an invoice who wants the total to net out to the right number.

Every calculation runs in your browser, and the result is captured in a shareable URL — so you can send a colleague or client the exact scenario you are looking at. When you have the number, the invoice generator turns it into a PDF, and the true cost of an employee calculator helps with the other side of the ledger.

Payment processing rates and surcharge laws both change, and neither is one-size-fits-all — so the calculator treats every number as an editable 2026 estimate rather than a fixed truth. The processor presets reflect commonly published US rates, but your actual rate depends on your plan, your volume, the card type, and the region; the correct move is to click a preset for a fast starting point and then overwrite the percentage and fixed fee with the exact rate your processor charges you. Likewise, the surcharge legality map reflects a reasonable read of the rules as of 2026, but state surcharge law is genuinely fluid — statutes get amended and court rulings shift what is enforceable — and card-network requirements apply on top of all of it.

Treat the outputs here as planning figures, not filed or binding numbers. They are excellent for quoting, pricing, reconciling and deciding, but anything you rely on for tax, accounting, or compliance — and absolutely any decision to add a surcharge to real customer transactions — should be confirmed with your accountant, your payment processor, and where relevant a professional familiar with your state's current surcharge rules. The tool is here to do the arithmetic and surface the questions; it is not a substitute for that professional confirmation.