Reverse Fee Calculator: What to Charge So You Net the Amount You Want

The instinct is to add the rate back on. You want $100, Stripe takes 2.9% plus 30 cents, so you charge $102.90 and consider it handled. Run the actual deduction and it falls apart. Stripe does not charge 2.9% of the $100 you wanted, it charges 2.9% of the $102.90 you actually ran. That is $2.98, plus the 30 cent fixed fee, for a total of $3.28. You net $99.62. You are 38 cents short, and adding another 2.9% will not close the gap, because whatever you add gets charged 2.9% as well.

The fix is one line of algebra. Call the amount you want to keep the net, the percentage the rate, and the per transaction flat charge the fixed fee. Then gross equals net plus fixed, all divided by one minus rate. For $100 net on Stripe's published US rate, that is 100.30 divided by 0.971, which is 103.2956, or $103.30 once you round to the cent. Check it against how the processor actually bills: 2.9% of $103.30 is $3.00, plus the 30 cent fixed fee is $3.30, and $103.30 minus $3.30 is exactly $100.00.

The fixed fee is what makes this ugly on small tickets, and it is the part people forget entirely. To net one dollar on 2.9% plus 30 cents you have to charge $1.34, an effective rate of 25.4%. To net $20 you charge $20.91. The percentage is almost irrelevant down there. This is also why the gap between the naive number and the correct number is not a constant: on a $100 sale it is 40 cents, on a $2,500 invoice it is $2.47, and it grows roughly in proportion to the amount because the compounding term dominates once the flat fee stops mattering.

One thing worth being clear about before the rest of this page gets complicated. Charging $103.30 for something is always allowed. That is a price. You can set your prices at whatever number makes your margin work, and nobody has any interest in how you arrived at it. Everything that follows is about what happens the moment you stop treating it as a price and start presenting the $3.30 to the customer as a fee.

The first case is an agreed number. You quoted $2,500, the client signed off on $2,500, and if $2,497.60 arrives you either eat the difference or have an awkward conversation about $2.40. Building the gross up into how you generate invoices is the difference between a rate card that means what it says and one that quietly runs 3% light. The same logic applies to contractor payouts, marketplace transfers, retainers, and any situation where a number was negotiated before a payment method was chosen.

The second is nonprofit donations, where the pattern is now close to universal. A donor picks $250, ticks a box offering to cover the processing cost, and the charge runs at a slightly higher figure so the organization banks the full $250. On PayPal's published US rate for receiving domestic donations, 2.89% plus $0.49, the correct charge is $257.94. PayPal takes $7.45 in percentage and $0.49 fixed, for $7.94, and $250.00 lands. The naive calculation of $250 times 1.0289 gives $257.23 and nets $249.31, which is 69 cents of donor generosity that evaporates for no reason.

The third is the case where you are pricing rather than passing anything on. A subscription business that knows every customer pays by card can simply set the price at the grossed up figure and never mention fees to anyone. This is the cleanest option available and it is worth saying plainly, because a lot of merchants reach for a surcharge when what they actually wanted was a price increase of three percent. A price increase has no registration requirement, no cap, no state law problem and no receipt disclosure obligation.

Visa's definition is broad and it is the one that matters: a surcharge is an additional fee or charge that a merchant adds to a consumer's bill for using a particular form of payment. A line item reading processing fee, card fee, convenience charge or 3% for card payments is that, whatever you call it in your invoicing software. Once you are surcharging, a stack of requirements applies at once. You must notify your acquirer at least 30 days before you start, and Mastercard requires that notice reach Mastercard as well as your acquirer. You must limit it to credit cards, because debit and prepaid cards cannot be surcharged at all, and that includes a debit card where the cardholder chose credit on the terminal. The surcharge amount has to be passed in a dedicated data field in the transaction message, which your acquirer populates. You must disclose it at the point of entry, at the point of sale, and separately on every receipt. And you must surcharge at either the brand level or the product level, not both.

Then there is the cap, and this is where the arithmetic on this page collides with the rules. Visa limits the surcharge to your merchant discount rate for that card or 3%, whichever is lowest. Mastercard's published maximum is 4%, and its cap is the lesser of that and your average effective rate for Mastercard credit acceptance, so if you take both brands you are effectively working to 3%. A full gross up of a 2.9% plus $0.30 flat rate does not fit inside 3% on any normal transaction. On a $100 sale the gross up is $3.30, which is 3.3% of the $100 price. On a $20 sale it is $0.91, which is 4.55%. The crossover point where a full gross up of that rate finally drops under 3% is around $2,308. If you cap the surcharge at 3% and charge $103.00 instead, your fee is $3.29 and you net $99.71, so you are still 29 cents down and you have accepted an entire compliance regime to recover most of it.

Enforcement is not theoretical. Visa says it uses yearly mystery shopping by outside auditors, and that the acquirer of a merchant identified as surcharging improperly may be assessed an immediate $1,000 fine. That flows to you through your processing agreement. Stripe's own surcharging documentation is blunt about where liability sits: you are fully responsible for any fines, penalties or losses arising from failure to adhere to applicable surcharging requirements. Stripe caps US surcharges at 3% and restricts them to credit cards in its own implementation, and it requires you to return the entire surcharge on a full refund and a prorated share on a partial one.

State law sits on top of all of this. Visa's own published understanding, dated 15 February 2024 and disclaimed as non authoritative, is that Connecticut, Maine, Massachusetts, Oklahoma and Puerto Rico prohibit surcharging, and that Colorado, Minnesota, New Jersey and New York impose requirements on it. If you operate in several states, the rule follows the location of each outlet, so you can surcharge in one and not another. There is also a consumer pricing angle that catches people who thought they had solved this. Under California's SB 478, in force since 1 July 2024, the advertised price must include all mandatory fees other than government taxes and reasonable shipping. The Attorney General's guidance answers no to advertising one price and separately stating that an additional percentage fee applies, and no to disclosing the extra fee before the customer finalizes the transaction. Fees for optional services do not have to be included, and the law does not reach purchases for commercial use, which is why a B2B invoice and a consumer checkout are genuinely different problems.

For a 501(c)(3) taking donations, the checkbox is on solid ground, and the reason is structural rather than a matter of anyone looking the other way. The donor is not paying a fee for using a card. They are choosing to make a larger gift. Nothing is being sold, so there is no bill to add a charge to, and the amount is voluntary, so it is not a mandatory fee under a price transparency law either. Keep it that way and it stays clean: leave the box unchecked by default, label it as increasing the gift rather than as a fee, and offer it on every payment method rather than only on cards. The moment it appears exclusively for card payers and is described as covering the card fee, you have built something that looks a lot more like a payment method contingent charge.

Worth checking your rate before you set the percentage, because charities frequently gross up against the wrong number. PayPal's published US schedule prices domestic donations at 2.89% plus $0.49, and confirmed charities who apply and are pre-approved get 1.99% plus $0.49. On the charity rate, netting $250 needs a charge of $255.58, not the $257.94 the standard donation rate requires. A default cover the fee percentage set to 3% or 4% because that felt about right is collecting more than the cost, which is defensible if you say so and awkward if you have told donors it covers the fee.

For a for profit merchant the same widget is a different animal. A checkbox at checkout offering to add the processing cost to a sale is a fee added to a consumer's bill for using a card, and the fact that the customer could have paid by ACH or check instead does not exempt it. Optional in the sense of the customer having chosen it is not the same as optional in the sense the rules care about. If you want to move card costs onto customers without surcharging, the sanctioned route is a cash discount, and Visa is specific about how it has to look: display only the card price, or display the card and cash prices side by side per item, and the total charged on a card must be the displayed total. Visa warns directly that a total reached by adding an extra fee for card payment at the final bill may be treated as a surcharge and subjected to the surcharge rules. In other words, a cash discount that is really a surcharge with better labeling is still a surcharge.

Refunds are the big one. Grossing up gets the right money in on the way through and does nothing for you on the way back out. Stripe's policy is that processing fees from the original transaction are not returned. Square's is that when you refund a payment, the processing fees for that payment are not refunded back to you. So on that $103.30 charge, refunding the customer in full costs you $103.30 out of pocket against $100.00 that ever reached you, and you are down the full $3.30. If you surcharged, you also have to return the surcharge in full on a full refund and prorate it on a partial one, which means you refund more than you netted. High return rate businesses should model this before deciding a gross up has solved anything.

The formula also assumes you know the rate, which is only reliably true on flat rate pricing. On interchange plus you do not know what a transaction costs until you know which card was presented, because a consumer debit card and a corporate rewards card can differ by well over a percentage point. You can gross up against your blended effective rate from last month's statement and be roughly right on average, but any individual transaction will land above or below, and a premium card on a large ticket can miss by real money. If you are on interchange plus and you need an exact net, price for the worst case card you actually see rather than the average.

It also assumes you picked the right rate off your own processor's schedule, which is easier to get wrong than it sounds. Square is the clearest example: on the Free plan, Square Online and Invoices run 3.3% plus 30 cents, while the eCommerce API runs 2.9% plus 30 cents, and keyed in or card on file transactions run 3.5% plus 15 cents on every plan. Those are three different answers for the same merchant depending on how the payment was taken. Gross up against the wrong one and you are off by 40 or 60 basis points before you start.

And there are costs that simply are not per transaction percentages, so nothing here reaches them. Chargeback and dispute fees land on top and are usually flat. International cards and currency conversion add percentage points that the domestic rate you typed does not include. Amex is often priced separately. Monthly platform fees, gateway fees and monthly minimums are not attached to any one sale and cannot be recovered a transaction at a time. Grossing up handles the arithmetic of one flat rate charge accurately and completely, and that is the whole of what it does.