Payment Fee Calculator

How it works

Choose a fee model that matches your payment agreement

The custom mode accepts a percentage fee and a fixed fee for each payment. Enter the full rate that applies to the transaction you want to model. Your country, payment method, card origin, settlement currency, and contract can change the applicable charge. When the agreement includes additional products or separate fees, combine only charges that share the same calculation base; this simple model cannot reproduce every processor’s fee structure.

The Stripe preset is restricted to the published US standard domestic online-card example: 2.9% plus USD 0.30, checked on October 13, 2026. Its currency is fixed to US dollars. It does not include international-card additions, conversion, manually entered cards, dispute charges, or other Stripe products. Follow the official pricing reference and use the custom mode when your agreement differs.

Work through a payment-fee and reverse-fee example

At 2.9% plus 0.30, a gross payment of 100 incurs 2.90 in percentage fees plus 0.30 in fixed fees. The total fee is 3.20 and the net receipt is 96.80. The effective fee rate is therefore 3.2% of the gross payment, which is higher than the quoted percentage because the fixed component also consumes part of the payment.

To receive a net 100 under those same assumptions, the rounded minimum gross charge is 103.30. Its fee rounds to 3.30, leaving exactly 100. Charging 103.29 leaves 99.99 after the same rounding convention. The reverse mode verifies the rounded net receipt instead of just displaying an unrounded algebraic answer. The result is arithmetic for a target receipt, not a recommendation about customer surcharges.

Compare the cost of several payments

The amount field is per payment. The transaction count multiplies the result across equal payments, with the fixed fee applied to each one. For ten payments of 100, the example model produces 32 in fees and 968 in net receipts. One payment of 1,000 produces a different fee because it incurs the fixed component once. Use separate calculations if the payment amounts differ.

The detailed row shows per-payment and aggregate amounts side by side. This is useful for comparing billing schedules, deposits, or recurring purchases. It does not account for the probability of refunds, failed collections, chargebacks, or fees charged on payouts. If you need a wider profitability view, combine processing costs with fulfillment expenses and overhead in the online seller profit calculator.

Read rounding, effective rates, and small-payment results

The custom mode lets you choose the smallest amount unit used by the calculation. Fees are rounded half up to that precision for each payment. Reverse calculations then find the smallest permitted gross amount that meets the target net. A processor may have additional rounding rules, minimum fees, or payment minimums; those are not inferred from the two fee inputs.

A zero gross payment has no meaningful effective percentage because the denominator is zero. A fixed fee larger than a small payment can also create a negative modeled receipt. These outcomes are displayed rather than hidden so you can see the effect of your assumptions. Save a named scenario with its currency and contract context, and refresh the inputs when the agreement changes.

Custom processing fees: formula and assumptions

Fee = rounded(gross × percentage + fixed fee). Net = gross − fee. Target gross is rounded up until net meets the target.

The amount is per payment; totals multiply it by the number of equal payments. Enter the complete percentage and fixed fee for your agreement. The model excludes fees not included in those inputs.

Stripe US domestic online cards: formula and assumptions

Illustrative US standard domestic online card fee = rounded(gross × 2.9% + $0.30).

US dollar preset checked against Stripe pricing on October 13, 2026. Standard domestic online cards only; excludes international cards, currency conversion, manually entered cards, disputes, additional products, and negotiated pricing. Use custom fees for a different contract or country.

Worked example

Reference example currency: USD. These fixed examples do not change with your calculator preferences.

Using the Custom processing fees example:

Find

Net amount after fees

Payment or target net amount ($)

100

Number of equal payments

1

Percentage processing fee (%)

2.9

Fixed fee per payment ($)

0.3

Amount decimal places

2 — cents

Fee = rounded(gross × percentage + fixed fee). Net = gross − fee. Target gross is rounded up until net meets the target.

Example result

• Custom percentage plus fixed-fee model. A small payment may have negative net receipts when the fixed fee exceeds the payment.
• Reverse calculations find the smallest charge at the chosen precision that meets the target after rounded fees. This is pricing arithmetic, not permission to impose a surcharge.

These are illustrative inputs. Change the values to explore a different scenario.

What to keep in mind

Use one currency throughout. Currency selection changes labels, not exchange rates. Calculate, then save a named scenario in My workspace to keep it in this browser; export a workspace backup to move it to another device.

Formula references

• Stripe: official US pricing and additional fees (opens in a new tab)

References explain the underlying methods; they do not imply endorsement or individual professional review of Finflo.

Common questions