15% versus 2.9% is not the real decision
Put the two rates next to each other and the gap looks enormous. A 15% commission against a 2.9% processor fee on €10,000 of monthly revenue is roughly €1,200 apart. That framing is also wrong in most storefronts, because switching your checkout does not switch Apple off.
Under the EU business terms effective 1 October 2026, an App Store app taking payment through its own processor still pays Apple a commission — 20% on standard terms, 10% where a reduced rate applies. Leaving the App Store entirely replaces that with a 5% Core Technology Commission. So the honest comparison is 15% against 10% plus 2.9%, not 15% against 2.9%. The calculator above resolves whichever of those applies to the region and date you pick.
On top of the fee arithmetic, moving checkout out of the app replaces one frictionless tap with a browser handoff, a payment form, and a card entry. Whatever share of buyers drops out at those steps comes straight off gross revenue, before any fee is applied. So the useful question is not which rate is lower — it is how large a conversion drop the alternative path can absorb before Apple IAP nets more. That is the break-even number this page calculates.
The costs that sit outside the processor's rate
Stripe's advertised rate covers card processing. It does not cover everything StoreKit was doing for you. Once you run your own checkout you typically take on tax calculation and remittance — or pay a merchant-of-record service that charges its own percentage on top of processing.
Refunds and chargebacks become your problem, including the disputes Apple previously absorbed. Failed renewals need dunning and card-update logic, and involuntary churn on a self-managed subscription is usually worse than on a store-managed one. Billing questions arrive in your support inbox instead of Apple's. Someone has to build, monitor, and maintain the whole path.
None of that is a reason to stay on StoreKit. It is a reason to compare net outcomes rather than rates, and to be honest about the conversion and operational cost of the switch when you do.
How to read the break-even number
The comparison above holds revenue constant and computes both scenarios at zero conversion loss, then reports the conversion drop at which they meet. If your own funnel data suggests a smaller drop than that figure, the alternative payment path is likely the better economics for you. If it suggests a larger one, Apple IAP probably wins.
Whether you may route payments outside the app at all, and on what terms, depends on your storefront and on your agreement with Apple. This calculator is an economic model, not a compliance check. Apple's own fee on the alternative path is included wherever the rule set for your region and date defines one, so read the scenario B column as a fee comparison rather than as an Apple-free best case.