The honest answer is that most self-published authors make very little, a minority make a middle income, and a small group make more than most traditionally published authors ever will. That spread is so wide that any single headline figure is close to useless. What helps more is knowing where the numbers come from, why they disagree with each other, and how to build an estimate for your own books.
What the surveys report
Two sources get quoted most often. The Alliance of Independent Authors commissioned CREATe at the University of Glasgow to analyse indie earnings, and the resulting survey found a median revenue of US$12,749 for 2022. ALLi's more recent income survey puts the median at around US$13,500. Both figures cover a specific group: authors who spend more than half their working time on writing and publishing, or who earn more than half their income from it. Hobbyists with one book out are not in that sample.
Written Word Media's 2025 indie author survey looks at a broader pool and reports monthly income instead. Roughly 44% of respondents earn US$100 a month or less. Around 20% sit between US$500 and US$5,000 a month, and about 8% clear US$10,000 a month. That survey skews towards authors who already buy book promotion, so it is not a random sample of everyone with a KDP account either.
Why the average is five times the median
The ALLi survey found a mean revenue of US$82,607 against that median of US$12,749, with almost 18% of respondents reporting more than US$100,000. A handful of very high earners drag the average upwards while the typical author sits far below it. When someone quotes an average indie author income at you, check whether they mean mean or median, and check who was allowed into the sample. Both choices can move the number by a factor of five or more.
The maths of one sale
Amazon pays 70% on ebooks priced inside its higher royalty band, which starts at US$2.99 and now runs up to US$12.99 after Amazon lifted the old US$9.99 ceiling in July 2026. Outside that band you get 35%. On the 70% tier Amazon also deducts a delivery fee based on file size, US$0.15 per megabyte in the US store, before calculating the royalty. So a US$4.99 ebook returns somewhere around US$3.30 rather than a clean US$3.49.
Print is thinner. Paperbacks pay 60% of list price minus the printing cost, and printing on a 300-page paperback eats a large share of a US$12.99 cover price. Kindle Unlimited pays per page read at a rate that moves each month, historically hovering near half a US cent, so a full read-through of a long novel can pay about the same as a sale.
What actually moves the number
Catalogue size predicts income more reliably than almost anything else in these surveys. Around 80% of authors with one to three books fall in the under-US$100-a-month band, while authors earning US$5,000 to US$7,500 a month have a median of roughly 30 published titles. The mechanism is simple enough: a reader who finishes book one can only spend more money with you if book two exists, and promotion spend gets recouped across the whole series rather than a single title.
Selling direct changes the per-sale figure too. Among Written Word Media respondents earning US$10,000 a month or more, roughly half sell direct from their own store. On a direct sale you keep the price minus payment processing and tax, which is closer to 90% than 70%, and you keep the customer's email address.
Costs come off the top
These are revenue figures, not profit. In the same survey, most authors spend somewhere between US$100 and US$999 per book on editing, and mid-range earners commonly spend US$100 to US$499 on a cover. Only a small minority spend above US$2,000 on editing, and the data shows no clear income advantage to going much higher. Add advertising, and a first book can take a year or more to clear its own production cost.
Model your own
Take your planned list price, work out the actual royalty after delivery fees or print costs, and multiply by a sales figure you can defend. Then subtract production and ad spend, and divide by the number of months it took. That number will be smaller than the headline surveys and closer to what lands in your bank account.
If you want more of each sale to stay with you, the Toolchest membership from •BulletPoint Publishing gives you an author website, mailing list, direct ebook sales, ARC distribution and a press kit for one flat monthly fee, instead of five subscriptions that grow as your list does. Have a look at what is included.