# How much does Substack take? Fee calculator versus Kit

Updated September 5, 2026.

## Quick verdict

Under the standard United States recurring-card assumptions below, Substack's direct fees are about 10.1% of gross revenue higher than Kit Commerce fees. That does not automatically make Kit better. Substack can still fit when its writer-first network and in-platform discovery are central to the business.

At 100 monthly charges of $10:

- Substack estimate: $166
- Kit Commerce estimate: $65
- Estimated monthly difference: $101

## Who this is for

Use this decision if you publish consistently, have a real audience-acquisition path or paying demand, and are comparing paid-newsletter economics. Skip it if publishing cadence, reader acquisition, or willingness to pay is unproven. In that case, validate first.

## Current assumptions

Substack estimate:

- 10% Substack platform fee
- 2.9% plus $0.30 Stripe card processing per charge
- 0.7% Stripe Billing fee for recurring payments

Formula: gross revenue multiplied by 13.6%, plus $0.30 per transaction.

Kit Commerce estimate:

- 3.5% plus $0.30 per United States dollar transaction

Formula: gross revenue multiplied by 3.5%, plus $0.30 per transaction.

These estimates exclude taxes, refunds, disputes, currency conversion, special card rates and paid plan costs outside the stated commerce fees.

## Decision outcomes

- Validate first: choose neither when the offer or acquisition path is unproven.
- Keep current: do not migrate when the current setup works and the benefit is unclear.
- Substack fit: keep or choose Substack when its writer-first network plausibly produces enough value to justify the fee premium.
- Kit fit: evaluate Kit when you already own the audience relationship and lower commerce fees, broader email operations or product breadth solve a real problem.

## Migration warning

Kit's current migration guidance says active paid Substack subscriptions do not transfer conveniently with payment details. A move may require canceling subscriptions and asking readers to subscribe again. Compare estimated recurring savings with reactivation risk, refund handling, archive recreation and communication time.

## Official sources

- [Substack payment-fee documentation](https://support.substack.com/hc/en-us/articles/18687769631252-How-can-readers-pay-for-a-subscription-on-my-Substack-publication)
- [Substack pricing explanation](https://support.substack.com/hc/en-us/articles/360037607131-How-much-does-Substack-cost)
- [Kit Commerce fees](https://help.kit.com/en/articles/4199324-sell-digital-products-with-kit-overview-and-faqs)
- [Kit paid newsletters](https://help.kit.com/en/articles/4587009-creating-a-paid-newsletter)
- [Kit migration from Substack](https://help.kit.com/en/articles/6393834-migrating-from-substack-to-kit)

## Affiliate disclosure

A genuine Kit-fit result on the interactive calculator can include AppNarrow's approved Kit affiliate link. AppNarrow may earn a commission from qualifying referrals at no additional cost to the buyer. Substack is not monetized here. Choose neither, keep current and Substack-fit outcomes remain valid.

[Use the interactive calculator](https://appnarrow.com/tools/substack-vs-kit-fee-calculator.html)