PAID NEWSLETTER ECONOMICS
How much does Substack take? Compare it with Kit.
Quick verdict: under the standard United States recurring-card assumptions used here, Substack's direct fee is about 10.1% of gross revenue higher than Kit's. That does not automatically make Kit better. Substack can still fit when its writer-first network and discovery are central to the business.
Official fee sources rechecked September 5, 2026. Estimates exclude taxes, refunds, disputes, currency conversion, special card rates, and any paid plan costs outside the stated commerce fees.
Fast example: at 100 monthly charges of $10, the current assumptions estimate $166 in Substack fees and $65 in Kit Commerce fees, a $101 monthly difference.
WHO THIS IS FOR
Use this when paid newsletter revenue is a real decision.
Best for a solo writer or creator comparing the economics of a paid newsletter on Substack and Kit. Skip it if you have not established a publishing cadence, audience source, or paid offer. In that case, validate first and avoid optimizing fees on revenue that does not yet exist.
THE MATH USED
Transparent estimates, not a revenue forecast.
Substack estimate: 10% Substack fee plus 2.9% + $0.30 Stripe processing and 0.7% Stripe Billing for recurring payments.
Kit estimate: 3.5% + $0.30 per transaction for United States dollar sales through Kit Commerce.
Main tradeoff: the percentage-fee difference is measurable; the value of Substack discovery is not. Judge whether the network plausibly creates enough incremental paid business to justify the premium.
SWITCHING COST MATTERS
Lower fees do not automatically justify a migration.
Kit's current migration guide says there is no convenient way to transfer active paid Substack subscriptions with payment details. A move may require canceling those subscriptions and asking readers to subscribe again in Kit.
Decision rule: compare the estimated recurring savings with subscriber reactivation risk, refund handling, archive recreation, and the time required to communicate the change. Keep Substack when the switching risk or network value plausibly exceeds the direct fee difference.
PRIMARY SOURCES
Verify current merchant terms before committing.
Substack official payment-fee documentation
Substack official pricing explanation
Kit official Commerce fee documentation
Kit official paid-newsletter documentation
AppNarrow uses current official-source research and does not claim hands-on testing, guaranteed discovery, guaranteed deliverability, or guaranteed earnings.
Affiliate disclosure: A genuine Kit-fit result can include AppNarrow's approved Kit affiliate link. AppNarrow may earn a commission from qualifying referrals at no additional cost to you. Substack is not monetized here. Choose neither, keep current, and Substack-fit outcomes are valid.