True Cost of BNPL Calculator
Enter your purchase details to see the effective APR, total cost with any late fees, and how it compares to a credit card.
A "Pay in 4" plan advertised at 0% interest costs the purchase price when every installment lands on time. The number that's harder to see is what the same plan costs once a payment slips, a longer-term loan carries an APR, or several plans run at once. This calculator puts that figure in plain terms: it takes the purchase amount, the provider's fee schedule, the plan length, and the number of missed payments, and returns an effective APR alongside the total dollar cost.
Two APR methods are shown side by side — a simple method and the TILA (Truth in Lending Act) method lenders use for disclosed loans — because the two can differ on short-term installments. The same result is placed next to the cost of the purchase on a credit card at a rate you choose, so the two financing paths sit next to each other rather than on separate pages. Nothing is entered on a server; the math runs in your browser.
Enter the total purchase price you're financing.
Choose the company offering the installment plan.
Select a provider first to see available plans.
How many scheduled payments you expect to miss or pay late. The payment taken at checkout cannot be late, so at most 1 of 4 can be.
The APR on the credit card you'd use as an alternative. US average is around 22%.
One missed payment: what it does to a Pay in 4 plan
Each cell is the total late fee a provider's published terms charge on an order when one installment is missed, followed by the TILA effective APR of the whole plan once that fee is included. The figures are computed from the same fee schedule and payment dates the calculator above uses.
| Provider | $100 order | $250 order | $500 order | $1,000 order |
|---|---|---|---|---|
| Affirm | $0 · 0% | $0 · 0% | $0 · 0% | $0 · 0% |
| Klarna | $7 · 123% | $7 · 49% | $7 · 24% | $7 · 12% |
| Afterpay | $8 · 140% | $8 · 56% | $8 · 28% | $8 · 14% |
| PayPal Pay Later | $0 · 0% | $0 · 0% | $0 · 0% | $0 · 0% |
| Zip | $7 · 123% | $7 · 49% | $7 · 24% | $7 · 12% |
On a $100 order, Affirm and PayPal Pay Later charge nothing, while one missed payment works out to an effective APR of 140% with Afterpay and 123% with Klarna, because an $8 fee is spread over only 6 weeks; the same $8 fee on a $1,000 order is 14%.
- Affirm and PayPal Pay Later publish no late fee on Pay in 4; a missed payment there shows as $0 and 0%, though it can still affect future approvals or be reported.
- Klarna and Afterpay cap total late fees on one order at 25% of the order value; at these order sizes a single missed payment stays under the cap, so no cell is reduced.
- Afterpay: Late fee up to $8 per missed installment, charged only after the payment is 10 days past due; total late fees on an order never exceed 25% of the order value.
- Zip: Late payment fee of $7, or the lower amount set for your state; Zip discloses the exact fee in your loan agreement. Zip charges an origination fee that varies with order size and plan; Zip shows it at checkout. That fee is not included above.
- Terms last verified September 21, 2026.
Monthly plans: interest on a $1,000 purchase
Longer BNPL plans carry a real APR, offered as a range that depends on credit approval. Each cell shows the total interest on a $1,000 purchase at the bottom and the top of the provider's published range for that plan length, using the calculator's amortisation. The last column is the same purchase carried on an average credit card for the same number of months.
| Plan length | Affirm 0–36% APR | Klarna 0–35.99% APR | Afterpay 0–36% APR | PayPal Pay Later 0–35.99% APR | Credit card 20.94–22.15% APR |
|---|---|---|---|---|---|
| 3 months | $0 – $61 | $0 – $61 | — | $0 – $61 | $35 – $37 |
| 6 months | $0 – $108 | $0 – $108 | $0 – $108 | $0 – $108 | $62 – $66 |
| 12 months | $0 – $206 | $0 – $206 | $0 – $206 | $0 – $206 | $117 – $124 |
| 24 months | $0 – $417 | $0 – $417 | — | $0 – $417 | $233 – $247 |
| 36 months | $0 – $649 | — | — | — | $355 – $378 |
- The APR you are offered depends on credit approval; the low end of a range is not guaranteed. Published ranges: Affirm, Klarna, Afterpay, PayPal Pay Later. “—” marks a plan length the provider does not offer.
- Credit-card rates are the Federal Reserve G.19, July 2026 release (Q2 2026 terms of credit) averages for all accounts and for accounts assessed interest, amortised monthly over the plan length.
- Terms last verified September 21, 2026.
Frequently asked
- How much does one missed Pay in 4 payment cost?
- One missed Pay in 4 payment costs $8 in late fees with Afterpay, $7 in late fees with Klarna and Zip, and nothing with Affirm and PayPal Pay Later. Klarna's $7 fee applies in full on orders of $28 or more and Afterpay's $8 fee applies in full on orders of $32 or more; on smaller orders their 25% cap on total late fees per order makes the fee lower. Zip has no cap, so its $7 fee applies in full on orders of any size. Because the plan runs about 6 weeks, that flat fee is a large share of a small order: on a $100 order it is an effective APR of 123% to 140%, and on a $1,000 order 12% to 14%.
- Is a 0% BNPL plan cheaper than a credit card?
- Only when the plan's APR really is 0%. On a $1,000 purchase over 12 months, a 0% monthly plan costs $0 in interest, while the same purchase on a credit card at the Federal Reserve's average 20.94% APR, paid off over the same 12 months, costs about $117 in interest. The 0% rate depends on credit approval: Affirm's published range runs to 36%, and at that rate the same 12-month plan costs about $206 in interest. At the top of the range, the plan costs more than the credit card.
How to read the result
The effective APR translates a flat fee into an annualized rate. Because a "Pay in 4" plan is repaid over roughly six weeks — the first payment is taken at checkout — even a small $7–8 late fee represents a large share of the amount financed for that short window. That is why a single missed payment on a modest purchase produces a headline APR in the tens of percent: try $200 with one missed payment and compare the two APR figures above. A longer-term installment loan spreads any stated APR across more months, so the same percentage carries a different dollar weight.
Fee data reflects each provider's publicly published schedule and is verified periodically, not in real time. Terms and fees last verified September 2026 — verify directly with your provider before completing a purchase. The calculator presents the numbers; the decision about any specific purchase is yours.