Substack Revenue Calculator

Substack’s commonly quoted platform share is 10% of subscription revenue, and paid subscriptions also carry payment processing on top of that, at a percentage plus a fixed amount per transaction. The fixed part is what makes the combined rate depend on price, and this calculator takes the platform share as an input rather than assuming a rate, so it stays correct if the published terms change.

That fixed component bites hardest at low monthly prices, which is where newsletter pricing usually sits. On a processing rate of 2.9% plus 0.30, the combined take is about 18.9% on a 5 monthly subscription, 15.9% at 10, 14.4% at 20 and 13.5% on a 50 annual charge. Net of both, a writer keeps roughly 81% at a 5 price and about 86% at 50. A single figure like 85% only holds around the 20 mark, not at the lower price points the platform’s own minimum sits near.

Revenue itself scales simply: paid subscribers multiplied by monthly price. The harder problem is converting free readers to paid. At a 5% conversion rate and a 5 monthly price, every 1,000 free subscribers represent 250 a month of gross subscription revenue, or 225 once the platform share is taken off, which is the basis the calculator uses for its upside row. Conversion depends heavily on whether readers need the content for work: professional and specialist newsletters are commonly described as converting several times better than general-interest ones, though published figures for this vary widely and are rarely measured on a consistent basis.

Run it with sensible defaults

Using paid subscribers of 500, an average monthly price of 5, free subscribers of 5,000 and a 5% free-to-paid conversion, gross monthly revenue is 2,500 and net revenue after a 10% platform fee is 2,250, or 27,000 a year. The upside row adds 1,125 a month from the free list at that conversion rate, giving a combined run rate of 3,375 a month and 40,500 a year if the conversion is achieved.

Entering the true combined rate changes that materially. At the 18.9% that a 5 price implies once processing is included, net monthly revenue falls to 2,027.50 and the annual figure to 24,330: a gap of 222.50 a month against the platform-fee-only figure. The fee input accepts a combined rate for exactly this reason, so entering 10 gives the platform’s share alone and entering the effective rate gives what actually reaches a bank account.

The levers in this calculation

Paid subscribers and average monthly price move net revenue proportionally, about 1% for each 1%, because they multiply together and then scale by whatever is left after the fee. The fee moves it in the opposite direction and far less: a 1% relative change in the fee rate, from 10 to 10.1, shifts net revenue by roughly 0.11%. Doubling the subscriber count and doubling the price produce the same result, since the two are interchangeable in the arithmetic, though a price rise usually costs some conversion while subscriber growth does not.

Free subscribers and the conversion rate do not enter the headline figure at all. Raising the free list from 5,000 to 10,000, or the conversion rate from 5% to 10%, leaves net monthly revenue at 2,250 and changes only the upside row, which moves from 1,125 to 2,250. That separation is deliberate: the headline is money currently arriving, and the upside row is a projection contingent on a conversion that has not happened.

How the math works

Gross monthly revenue is paid subscribers multiplied by average monthly price. Net monthly revenue is gross multiplied by one minus the fee rate, and the annual figure is twelve times that. The upside row applies the same arithmetic to the free list: free subscribers multiplied by the conversion rate, then by price, then net of the fee.

Rearranged, the subscriber count needed for an annual target is that target divided by twelve times the price times one minus the fee. At a 5 monthly price and a 10% platform fee that is about 926 subscribers for 50,000 a year, 1,852 for 100,000 and 9,259 for 500,000. Doubling the price halves each of those figures, which is why pricing decisions move the required audience size more than almost anything else.

What this doesn't capture

Churn is the largest omission. The model holds the subscriber count constant, whereas real lists lose paying subscribers every month and have to replace them before any growth registers. Annual plans are usually priced below twelve times the monthly rate and are typically retained longer, so a list split between monthly and annual behaves differently from either modelled alone, and the average monthly price entered here has to be a blend.

The fee input takes a single percentage, so the fixed part of a processing charge has to be folded in as a share of price rather than entered separately, and that share moves whenever the price does. Refunds, chargebacks, currency conversion on cross-border subscriptions, and any income tax on the earnings all sit outside the model. The upside row is a projection rather than revenue, and treating it as booked income overstates what is actually arriving.