What Are BNPL Fees?
Buy now, pay later (BNPL) fees are the amounts merchants pay providers such as Klarna, Afterpay, Affirm, Sezzle, and Zip to offer installment payments at checkout. Providers typically deduct their fee from the purchase amount and pay the merchant upfront, while they collect installments from the customer.
BNPL fees are often higher than standard card-processing fees, so compare the added cost with any extra orders or larger baskets BNPL may generate. Provider rates and customer terms vary by contract and market; the Consumer Financial Protection Bureau’s BNPL market report explains how these products work and how the market has developed.
BNPL Fee Formulas
Monthly orders = Monthly BNPL revenue ÷ Average order value
BNPL fee per order = (Average order value × BNPL rate) + BNPL fixed fee
Monthly BNPL fees = (Monthly BNPL revenue × BNPL rate)
+ (Monthly orders × BNPL fixed fee)
Standard card fees = (Monthly revenue × Standard rate)
+ (Monthly orders × Standard fixed fee)
Extra BNPL cost = Monthly BNPL fees − Standard card fees
The calculator compares estimated BNPL charges with the standard card-processing rate and fixed fee you enter. Use your signed provider rates where available; published or estimated rates are not a substitute for your contract.
How to Use This Calculator
- Enter Monthly Revenue — total monthly sales processed through BNPL providers, not your store’s entire revenue if only some customers use BNPL.
- Enter Average Order Value — the average value of BNPL orders. This helps estimate the number of transactions and the fixed-fee portion of the total.
- Enter Standard Rate — your card-processing percentage rate, such as the rate shown on your processor statement.
- Enter Standard Fixed — the fixed fee charged per card transaction. Use the same currency as your revenue and order value.
- Compare the results — review estimated provider fees, monthly costs, per-order costs, and the extra cost compared with standard cards. If you process international orders, check whether currency conversion or cross-border charges also apply; our Currency Conversion Fee Calculator can help estimate those costs.
Step-by-Step Example
A Shopify home-goods store processes $24,000 in monthly BNPL sales with an average BNPL order of $120. For this estimate, assume a BNPL rate of 5.99% plus $0.30 and standard card processing at 2.9% plus $0.30.
| Calculation | Arithmetic | Result |
|---|---|---|
| Monthly BNPL orders | $24,000 ÷ $120 | 200 |
| BNPL percentage fees | $24,000 × 0.0599 | $1,437.60 |
| BNPL fixed fees | 200 × $0.30 | $60.00 |
| Total BNPL fees | $1,437.60 + $60.00 | $1,497.60 |
| Standard card percentage fees | $24,000 × 0.029 | $696.00 |
| Standard card fixed fees | 200 × $0.30 | $60.00 |
| Extra BNPL cost | $1,497.60 − $756.00 | $741.60/month |
The extra cost is about $3.71 per order. To judge whether BNPL pays off, compare that amount with the contribution profit from additional orders or increased basket size—not just with total sales.
BNPL vs. Standard Card Processing
BNPL can improve checkout conversion or average order value, but results depend on the product, customer base, and how payment options appear at checkout. Industry estimates sometimes report conversion gains of 20–30% and average-order-value gains of 30–50% on eligible purchases; treat these as hypotheses to test, not guaranteed outcomes.
A useful decision rule is to ask whether the extra gross profit from BNPL-driven sales exceeds the added processing cost. For a store with thin product margins, a lift in revenue may still reduce profit if the extra sales do not cover provider fees, discounts, fulfillment, and returns. The Shop Pay Installments Cost Calculator can help compare installment costs with standard processing.
The CFPB notes that BNPL products commonly split purchases into installments, but terms differ across providers. Read your merchant agreement for payout timing, refunds, disputes, and eligibility rules rather than assuming every provider handles them identically.
Estimated Merchant Fee Benchmarks
These are typical estimates, not guaranteed quotes. Contract terms, sales volume, industry, and transaction mix can change the rate; use your actual offer when available.
| Provider | Estimated merchant fee |
|---|---|
| Klarna | ~5.99% + $0.30 |
| Afterpay | ~6% + $0.30 |
| Affirm | ~5.9% + $0.30 |
| Sezzle | ~6% + $0.30 |
| Zip | Varies by contract |
6 Tips to Evaluate BNPL Costs
- Change your assumed monthly BNPL share from 10% to 25% of sales and see how quickly total fees grow; avoid applying BNPL costs to revenue that still pays by card.
- Test an average order value of $65 versus $95. The percentage fee rises with order size, while fixed fees apply per transaction, so compare both effects.
- Run a checkout test for one product category at a time. Compare conversion and contribution profit for eligible BNPL shoppers against a similar period without the option.
- Check the break-even order lift before promoting installments. If BNPL adds $4 in cost to an order, the extra gross profit from the change must exceed that amount.
- Review refund and dispute terms before enabling a provider. Use the Chargeback Cost Calculator to model the broader cost of disputes beyond payment fees.
- Ask providers for a volume-based quote. A written offer lets you compare effective fees with the same assumptions; the FTC’s advertising guidance also explains why performance claims should be supported before you use them in promotions.
Frequently Asked Questions
How much do BNPL providers charge merchants?
Most BNPL providers charge merchants 5.5–7% plus $0.30 per transaction. Klarna charges approximately 5.99% + $0.30, Afterpay approximately 6% + $0.30, Affirm approximately 5.9% + $0.30, and Sezzle approximately 6% + $0.30; rates may be negotiable for high-volume merchants. This is roughly double a standard credit card processing rate, though the exact difference depends on your card contract and BNPL agreement.
Which BNPL provider is cheapest for merchants?
Rates are similar across providers, commonly around 5.5–6.5%, but Affirm and Klarna may offer lower rates to some high-volume merchants. The cheapest option depends on your negotiated contract and other terms, so enter actual rates in the calculator to compare providers side by side.
Is BNPL worth the higher merchant fees?
For many stores, it can be: BNPL is often associated with conversion increases of 20–30% and average-order-value increases of 30–50% on eligible orders, but results vary by store. If the added profit from those gains exceeds the roughly 3% fee premium over standard cards, BNPL may be profitable; stores with order values above $100 and in fashion, electronics, and home goods are often cited as strong candidates.
What is the difference between Klarna, Afterpay, and Affirm?
All three offer Pay in 4 installments, while Klarna also offers Pay in 30 days and longer financing. Affirm offers longer-term financing, typically 3–36 months, and powers Shop Pay Installments; Afterpay is popular with younger shoppers. Merchant fees are similar, so compare customer reach, product fit, and your negotiated terms.
Do BNPL providers pay merchants upfront?
Yes, major BNPL providers generally pay merchants the order amount upfront minus their fee, then collect installments from customers. The provider assumes the credit risk for the installment payments, but merchants should still review their contract for rules on refunds, disputes, and order eligibility.
About This Calculator
The Klarna, Afterpay & BNPL Fee Calculator was built for Shopify merchants by Luis Dev Studio to compare estimated provider costs with standard card processing. For help comparing payment costs or improving your Shopify setup, contact us or explore our services.
Updated by Luis Gonzalez · Jun 5, 2026