Payment Gateway Fee Comparison Calculator

What This Calculator Does and Why It Matters

Every time a customer pays you online, your payment gateway takes a cut. That cut might seem small — 2.9% here, 30 cents there — but across thousands of transactions a month, the difference between gateways can add up to hundreds or thousands of dollars annually. Choosing the wrong gateway means leaving real money on the table every single month.

This free payment gateway fee comparison calculator lets you enter your actual sales volume and average transaction size, then compares up to four gateways side by side. It shows you the total monthly cost for each, including percentage fees, flat per-transaction fees, monthly platform fees, and chargeback costs. The result is a clear table that tells you which gateway is cheapest for your specific business.

For a broader overview of how payment processing works, Investopedia’s payment gateway explainer is a solid starting point. If you are also running an e-commerce store and want to compare full platform costs, our Shopify vs WooCommerce Total Cost of Ownership Calculator covers the full picture beyond just processing fees.

How to Use This Calculator

Step-by-Step Instructions

1. Enter your monthly transaction volume in dollars — this is your total revenue processed through the gateway each month.
2. Enter your average transaction size — divide your total volume by the number of transactions if you are not sure.
3. Enter your estimated number of monthly chargebacks — this is often zero for small businesses but can matter at scale.
4. Review or customize the four gateway settings — the calculator defaults to Stripe, PayPal, Square, and a custom field, but you can rename and edit any of them.
5. For each gateway, enter the percentage rate, flat per-transaction fee in cents, monthly platform fee, and chargeback fee.
6. Click Compare Gateways to see total monthly costs and effective rates for each gateway side by side.

The Formula Explained

Breaking Down the Formula

The total monthly cost for each payment gateway is calculated by combining three types of fees. The transaction fee portion comes from applying the percentage rate to your total monthly volume and adding the flat per-transaction fee multiplied by the number of transactions. The monthly fee is added as a fixed cost regardless of volume. Chargeback fees are multiplied by the number of estimated chargebacks.

Total Monthly Cost = (Volume × % Rate) + (Number of Transactions × Flat Fee) + Monthly Fee + (Chargebacks × Chargeback Fee)

The effective rate is simply the total monthly cost divided by your total volume, expressed as a percentage. This is the most useful number for comparing gateways because it normalizes all fees — including flat fees and monthly charges — into one comparable figure.

Example Calculation with Real Numbers

Say your monthly volume is $10,000 with an average transaction of $50, so you process 200 transactions. You compare Stripe (2.9% + $0.30) against a gateway charging 2.2% + $0.20 with a $10 monthly fee.

Stripe: ($10,000 × 2.9%) + (200 × $0.30) = $290 + $60 = $350 total. Effective rate = 3.5%. Custom gateway: ($10,000 × 2.2%) + (200 × $0.20) + $10 = $220 + $40 + $10 = $270 total. Effective rate = 2.7%. The custom gateway saves $80 per month — $960 per year — at this volume.

When Would You Use This

Real Life Use Cases

This calculator is useful any time you are setting up a new online store, switching platforms, or simply reviewing your current costs. It is especially valuable when your business is growing and the gateway you chose at low volume is no longer the cheapest option at your current scale.

Many businesses accept the default gateway offered by their e-commerce platform without comparing alternatives. For Etsy sellers, our Etsy Seller Profit Calculator with Offsite Ads factors in platform and transaction fees together. For Amazon merchants, the Amazon FBA Storage Fee and ROI Calculator covers the full cost picture on that marketplace.

Specific Example Scenario

A subscription box company processes $50,000 per month with an average order of $45. They are currently using PayPal at 3.49% + $0.49 per transaction. Running this calculator, they discover that switching to a gateway at 2.2% + $0.20 with a $25 monthly fee would save them over $500 per month — $6,000 per year — a significant operational savings that funds additional marketing spend.

Tips for Getting Accurate Results

Use Your Real Volume, Not a Round Number

The difference between a $8,000 and $12,000 monthly volume can completely flip which gateway is cheapest, especially when one gateway has a monthly platform fee and the other does not. Pull your actual processed volume from your current gateway dashboard and use that number for the most accurate comparison.

Check for Volume Discounts

Many gateways offer custom rates for businesses processing over $50,000 or $100,000 per month. The default rates in this calculator are standard published rates. If your volume qualifies for a custom rate from a specific gateway, enter that rate manually in the custom gateway field to see the true comparison.

Factor In the Full Cost, Not Just the Percentage

According to the Federal Reserve’s consumer credit reports, businesses often underestimate payment processing costs by focusing only on the percentage rate and ignoring flat transaction fees and monthly costs. If you process many small transactions, a gateway with a low percentage but a high flat fee per transaction can end up being more expensive than one with a slightly higher percentage and a lower flat fee.

Frequently Asked Questions

What is a payment gateway?

A payment gateway is the technology that authorizes and processes credit card and digital payments in an online store or point-of-sale system. It securely transmits transaction data between the customer’s bank and your merchant account, and charges fees for each transaction it processes.

What is an effective rate for payment processing?

The effective rate is the total percentage of your revenue that goes to payment processing fees when all costs — percentage fees, flat fees, monthly fees, and chargebacks — are combined. It is the most useful single number for comparing gateways because it accounts for every fee type in one figure.

What are the standard fees for Stripe?

Stripe’s standard online processing rate is 2.9% plus $0.30 per successful transaction. There is no monthly fee for the basic plan. Stripe also charges fees for international cards, currency conversion, and disputes. These are the rates used as defaults in this calculator.

When does a monthly gateway fee make sense?

A gateway with a monthly subscription fee but a lower per-transaction rate can be cheaper if your volume is high enough. The break-even point is when the savings from the lower transaction rate exceed the monthly fee. This calculator shows you that crossover instantly by comparing total costs at your actual volume.

What is a chargeback and how does it affect fees?

A chargeback is when a customer disputes a transaction and the bank reverses the charge. Most gateways charge a fee of $15 to $25 per chargeback, and if your chargeback rate exceeds 1%, you may face additional penalties or account termination. Even a few chargebacks per month can add meaningfully to your total processing cost.

Can I negotiate payment gateway rates?

Yes, especially if you process over $10,000 per month. Many gateways will offer custom pricing if you ask, particularly for businesses with consistent volume and low chargeback rates. Use this calculator to see how much a 0.2% or 0.3% rate reduction would save annually — that figure is a strong negotiating point.

Is Stripe always the cheapest option?

Not necessarily. Stripe is competitive for average-sized transactions, but for businesses with very small average transaction sizes, the $0.30 flat fee adds up quickly and a gateway with a smaller flat fee may be cheaper overall. The best gateway depends entirely on your volume, average transaction size, and monthly fee tolerance.

What is the difference between a payment gateway and a merchant account?

A merchant account is a type of bank account that holds funds from card transactions before they transfer to your business account. A payment gateway is the technology that processes and authorizes the transaction. Some providers like Stripe and Square combine both functions into one, while traditional processors keep them separate with separate fee structures.

Conclusion

Choosing the right payment gateway is not just a one-time decision — it is an ongoing cost management opportunity. As your sales volume grows, the cheapest gateway at $5,000 per month may no longer be cheapest at $50,000 per month. This free payment gateway fee comparison calculator gives you the numbers to make that decision at any volume.

Run the comparison with your current gateway as one of the options and at least two alternatives. The savings might surprise you. Use ToolCR’s full suite of e-commerce and business tools to track costs across your entire operation.