Payment Processor Comparison
Compare what Stripe, PayPal, Square, and Shopify Payments actually cost on your volume — enter your numbers, see ranked monthly and annual costs, effective rates, and where interchange-plus wins.
Share of payments made with non-US-issued cards.
| Provider | Monthly cost | Annual cost | Effective rate | vs cheapest |
|---|---|---|---|---|
| Interchange-plus (your quote)Editable — enter the all-in rate from an acquirer quote. Default is illustrative, not a published price. | $1,200.00 | $14,400.00 | 2.40% | cheapest |
| Square — online via APISquare adds no international card surcharge. | $1,650.00 | $19,800.00 | 3.30% | +$5,400.00/yr |
| Shopify Payments — Grow ($105/mo)Subscription included in the totals below. | $1,705.00 | $20,460.00 | 3.41% | +$6,060.00/yr |
| Stripe | $1,725.00 | $20,700.00 | 3.45% | +$6,300.00/yr |
| Shopify Payments — Basic ($39/mo)Subscription included in the totals below. | $1,739.00 | $20,868.00 | 3.48% | +$6,468.00/yr |
| Square — online store (free plan) | $1,850.00 | $22,200.00 | 3.70% | +$7,800.00/yr |
| PayPal — card processingUnbranded card fields; branded PayPal Checkout costs 3.49% + 49¢. | $1,896.67 | $22,760.04 | 3.79% | +$8,360.04/yr |
| Shopify Payments — Advanced ($399/mo)Subscription included in the totals below. | $1,899.00 | $22,788.00 | 3.80% | +$8,388.00/yr |
Flat rates are the published US online card prices, verified against each provider's official pricing page (see date below). Real interchange-plus costs vary with your card mix — debit-heavy volume lands lower, corporate/rewards-heavy higher. At scale, routing transactions across more than one of these is how the blended rate drops further.
Frequently asked questions
Who is the cheapest payment processor?
It depends on your volume and mix — which is the point of this tool. At small volume the flat-rate providers are nearly identical and convenience should win. As volume grows, differences compound: Square skips international surcharges, Shopify plans buy lower rates with subscriptions, and above roughly $20–50k/month an interchange-plus merchant account usually beats every flat rate.
What is an effective rate and why does it matter more than the headline rate?
Total fees ÷ total volume. Fixed per-transaction fees hit small orders hard: at a $20 average order, Stripe’s 30¢ adds 1.5 percentage points; at $200 it adds 0.15. Two stores on identical "2.9% + 30¢" pricing can have wildly different effective rates.
When is interchange-plus worth it?
When your volume justifies underwriting and statements: commonly beyond $20k–$50k/month. You pay the true network cost plus a transparent markup, which typically lands 30–100bps below flat rates — but you take on a merchant account application and less polished tooling.
Can I use more than one processor at once?
Yes, and at scale you should: route each transaction to the cheapest or best-approving option, keep a fallback for outages, and gain negotiating leverage. That is payment orchestration — the logical next step once this table shows meaningful gaps on your volume.