What this comparison includes
Card processors publish rates as a percentage plus a fixed fee per payment, which makes it hard to compare them at your real volume. The calculator turns your monthly sales and average sale into a number of payments, splits them between online and in person, and applies each provider's standard US rates:
- Stripe: 2.9% + 30¢ online, 2.7% + 5¢ in person with Terminal, +1.5% for foreign cards.
- Square: Free plan 3.3% + 30¢ online and 2.6% + 15¢ in person; Plus ($49/month) 2.9% + 30¢ and 2.5% + 15¢; Premium ($149/month) 2.9% + 30¢ and 2.4% + 15¢.
- PayPal: 2.99% + 49¢ when buyers pay by card, 3.49% + 49¢ when they use PayPal Checkout, +1.5% for international buyers. PayPal is only compared for online sales.
Worked example
An online store sells $30,000 a month with an average order of $60 (500 payments), 10% of them on foreign cards. Monthly cost: Stripe $1,065, Square Plus $1,069, Square Free $1,140, PayPal card payments $1,187 and PayPal Checkout $1,337. Choosing Stripe over PayPal Checkout saves about $3,260 a year.
The fixed fee per payment matters more than the percentage when your average sale is small. At a $10 average, the 30¢ online fee alone is 3% of every sale, and PayPal's 49¢ is almost 5%. For a closer look at one provider, use the Stripe, Square or PayPal fee calculator.
Limitations
This compares standard published US pricing only. High-volume businesses can usually negotiate interchange-plus or custom rates, which this tool cannot know. Chargebacks, refunds, hardware, monthly software and currency conversion are excluded. Square's in-person rate applies to foreign cards too, so the foreign-card share only affects online sales. Other providers (Adyen, Helcim, Clover and bank merchant accounts) may be cheaper for some businesses.
Sources
Stripe pricing, Square pricing and PayPal merchant fees, checked October 7, 2026.