ECOMMERCE MANAGER
Subscribe
ECOMMERCE MANAGER

Free Tool

Payment Processor Fee Calculator

Enter your monthly card volume, average order value, and card mix to see your true effective rate across Stripe, Shopify Payments, PayPal, Helcim, Adyen, Square, and Authorize.net. We rank by total monthly cost, not the headline rate, and show what you'd save against your current processor.

$
$
≈ 2,941 transactions / month
Advanced
Adds each processor's per-dispute fee to its total.
Switching from Stripe to Adyen
Save $2,814/mo
$33,768 a year · 34.6% lower processing cost
Adyen Lowest cost Interchange-plus
$5,318
per month
2.13%
effective rate
Works on: Adobe Commerce BigCommerce Shopify Plus
Interchange++ pricing: $0.13 processing fee + interchange + scheme fees. Enterprise-oriented.
Helcim Interchange-plus
$5,921
per month
2.37%
effective rate
Works on: WooCommerce BigCommerce Shopify
Interchange-plus, no monthly fee. Markup falls further at higher volume tiers.
Authorize.net Interchange-plus
$6,093
per month
2.44%
effective rate
Works on: WooCommerce BigCommerce Adobe Commerce
Gateway model: $25/mo + $0.10/txn on top of an interchange-plus merchant account.
Stripe Your processor Flat rate
$8,132
per month
3.25%
effective rate
Works on: Shopify BigCommerce WooCommerce Adobe Commerce Wix
Default flat rate for online card payments. Same rate regardless of card type.
Shopify Payments Flat rate
$8,132
per month
3.25%
effective rate
Works on: Shopify
Basic plan online rate. Lower on higher Shopify tiers. Only available on Shopify.
Square Flat rate
$8,132
per month
3.25%
effective rate
Works on: WooCommerce Wix Square Online
Online / e-commerce flat rate.
PayPal Flat rate
$8,916
per month
3.57%
effective rate
Works on: Shopify BigCommerce WooCommerce Adobe Commerce Wix
Standard online card rate. Express Checkout / wallet rates can differ.
How we calculate this

For your current card mix, blended interchange is 1.745% + $0.110 per transaction.

Flat rate: volume × rate + transactions × fixed fee + monthly fee. Card mix is ignored, which is why a flat rate overcharges debit-heavy stores.

Interchange-plus: blended interchange (above) + the processor's markup % and per-transaction markup + monthly fee. Interchange is set by the card networks and is identical across interchange-plus processors.

Where a processor publishes volume tiers, the tier matching your volume is applied automatically.

What this doesn't include

Refund handling, cross-border and currency-conversion surcharges, AmEx surcharges where they apply, PCI compliance fees, payout-timing cash-flow differences, and negotiated enterprise rates above published pricing. Chargeback fees are included only when you enter a chargeback count under Advanced.

Default rates are 2026 card-not-present ballparks and are editable by the site owner. Use a recent processor statement for exact figures.
Compare these platforms in full

Payment processing fees, answered

How is the effective rate calculated for each processor?
Effective rate is total monthly fees divided by monthly card volume, expressed as a percentage. For flat-rate processors that is volume times the percentage rate, plus a fixed fee on every transaction. For interchange-plus processors it is the blended interchange for your card mix, plus the processor markup percentage and per-transaction markup, plus any monthly fee.
Why does card mix change the interchange-plus cost but not the flat-rate cost?
Flat-rate processors charge the same percentage no matter what card a customer uses, so debit, rewards, and Amex all cost you the same. Interchange-plus passes the actual network interchange through at cost and only marks it up, so a debit-heavy mix lowers your cost while a rewards-heavy mix raises it. That gap is why high-debit merchants tend to overpay on flat-rate pricing.
Where do the default rates come from and can I trust them?
Defaults are card-not-present (online) ballparks for 2026 and are starting points, not quotes. Interchange is set by the card networks and is identical across interchange-plus processors. Your real interchange depends on your exact card mix, ticket size, and merchant category, so use a recent processor statement for precise numbers.
Does a lower headline rate always mean lower total cost?
No. Per-transaction fixed fees punish low average order values, and monthly or gateway fees favor higher volume. A processor with a slightly higher percentage but a lower fixed fee can win at low AOV, and the reverse holds at high AOV. The calculator ranks by total monthly cost for your inputs rather than headline rate for that reason.
Which ecommerce platforms support each processor?
Each result lists the platforms that natively support that processor. Shopify Payments is exclusive to Shopify. Stripe and PayPal are supported across nearly every platform. Adyen skews toward enterprise platforms like Adobe Commerce and Shopify Plus. Authorize.net is a gateway typically paired with an interchange-plus merchant account.
Rates out of date? Suggest a correction