Free calculator
Every calculator on this subject computes one gateway at one rate. Real stores take money through three or four, and one order can be charged by two of them. This works out the blended rate, which is the one that reaches your P&L.
Your blended payment fee rate
2,18%
23Fees a month
€1.649,27
Per order
€2,36
Charges
728
28 orders split
What you take
Your gateways
These rates are placeholders, not quotes. Copy the ones off your own statements: they differ by plan, by country and by whatever you negotiated.
What goes wrong
↑ ↓ to nudge, Shift for ten. Commas or dots both work.
Where the fees come from
Split payments cost you €8,12 a month on exactly the same revenue, because both halves pay a fixed fee and the percentage is rounded twice. A refund gives none of this back: the fee stays as charged on the original order.
€1.649,27 a month across 728 charges, or €2,36 on an average order. This is the figure that lands on line 23, not any single gateway’s advertised rate.
An estimate from flat rates. In nouz every order is priced from the costs of its own day.
A payment fee calculator applies each gateway's percentage and fixed fee to your real payment mix and returns what payments cost you per month, per order and as a blended rate. The blend matters because no store pays one rate: money arrives through several gateways at different prices.
The formula
Every gateway prices the same way: a percentage of the gross amount it moved, plus a fixed fee on each transaction. Two numbers, and they behave in opposite directions as the basket changes.
The percentage is basket-neutral. Whatever the order size, it takes the same slice, so a store with a €20 basket and a store with a €500 basket pay the same rate on it.
The fixed fee is not. Twenty-five cents is 1,25% of a €20 order and 0,05% of a €500 one, a fiftyfold difference in what the same fee costs. That is why a low-basket store should negotiate the fixed leg and a high-basket store should negotiate the percentage, and why comparing two gateways on their headline rates alone tells you almost nothing.
One more detail decides the base: the percentage is charged on the gross amount, VAT and shipping included, because that is what the gateway actually moved. Applying it to net revenue understates the cost by roughly the VAT rate.
Where it goes wrong
Each of these is a real mechanism, each one moves the answer, and none of them is visible if you multiply one rate by one revenue figure.
An order settled with a gift card and a card, or split across a part payment, arrives at the gateway as two transactions on roughly half the money each. The percentage lands on the same total, but the fixed fee is charged in full on both halves, and the percentage is rounded twice instead of once.
It is a small effect per order and a real one per month. Model it by transaction count, never by order count.
A gateway charges on what it moved: the product price, the shipping the customer paid, and the VAT on both. Applying the advertised rate to net revenue quietly removes about a sixth of the base at German rates and reports a fee that is correspondingly too small.
On the calculator above, the amount charged is the gross figure for exactly this reason.
A dispute takes the order value back and charges a fee for the privilege, often €15 to €25. Those are different things and they belong on different lines: the amount behaves like a return, and the fee is a transaction cost.
A chargeback is also not a return in the logistics sense. Nothing came back, so there is no return processing cost to add, however much it feels like one.
The gateway keeps its cut on the original charge. That is the conservative treatment and it is the correct one, and it surprises people, because a refund feels like an undo.
It is also why a high return rate costs more than the refunded revenue: the outbound parcel was shipped, the fee was charged, and neither comes back.
Worked example
The calculator’s own defaults, not a customer’s books. 700 orders in a month at an average charge of €108,00 gross, which is €75.600 through the gateways. Money arrives 62% through Shopify Payments, 24% through PayPal and 14% through Klarna, at the placeholder rates in the calculator. 4% of orders are paid with two methods, and one order in 667 is disputed at a €15 fee.
Not one of the three headline rates is the answer. Shopify Payments alone is the cheapest of them, and a store that budgeted on its rate would be about a third short.
€1.649,27 a month, a blended 2,18%, and €2,36 out of every order. The percentage leg is about €1.424 of it and the fixed leg about €210, which at this basket size means the rate negotiation worth having is on the percentage.
The 28 split orders cost €8,12 extra on identical revenue. Small, and worth knowing it exists, because it is a cost that scales with a payment method mix rather than with sales.
In the app
A calculator works from flat rates you type once. nouz prices every single order from the cost rules that were in force on that order's own date, and rebuilds the same statement every night from your own orders and your own ad spend.
More calculators
Each one is a different question about the same statement. All 32 are free, and none of them asks you to sign up.
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The long version
Want the long version rather than the arithmetic?
On an €85 order€1,92kept by the gateway, refund or not6 min readNobody gives the payment fee back when you refundA refund returns the money and not the fee. Why that makes a refunded order worse than a sale that never happened, and how it should sit on a statement.Nobody gives the payment fee backnouz prices every charge from the rule that was in force on its own date, per gateway, so the blended rate is measured rather than estimated.