KDP Royalty Calculator 2026: How Much Do AI Books Actually Make?

"How much do KDP books actually make?" is the most-Googled question in self-publishing — and the most poorly answered. The honest version isn't a single number; it's a formula. Once you understand the per-format royalty math, you can predict any KDP book's earnings within ±20% before you even publish. Here's the 2026 calculator every AI-assisted author should have memorized.

The four KDP royalty paths

• Kindle ebook (70%): $2.99–$9.99 list price → 70% royalty minus delivery fee (~$0.06 per book in the US).
• Kindle ebook (35%): any price outside $2.99–$9.99, or non-exclusive territories → 35% royalty, no delivery fee.
• Paperback: 60% royalty minus printing cost (~$0.85 fixed + $0.012 per page in black-and-white, US).
• Hardcover: 60% royalty minus printing cost (~$6.80 fixed + $0.012 per page, US).

The ebook formula

Royalty = (List price × 0.70) − $0.06. A $4.99 ebook earns $3.43. A $7.99 ebook earns $5.53. A $9.99 ebook earns $6.93. Below $2.99 you drop to 35%, so a $0.99 ebook earns just $0.35 — which is why $0.99 should only be used as a launch promo, never a permanent price.

The paperback formula (US, black-and-white interior)

Royalty = (List price × 0.60) − ($0.85 + $0.012 × page count). A 250-page paperback at $12.99 earns: ($12.99 × 0.60) − ($0.85 + $3.00) = $7.79 − $3.85 = $3.94 per copy. Push that book to 350 pages and the printing cost rises to $5.05, dropping royalty to $2.74. Length helps with KU — but it taxes paperback profit. Pick your trade-off deliberately.

The hardcover formula

Royalty = (List price × 0.60) − ($6.80 + $0.012 × page count). Hardcovers only make sense above ~$22.99 list. A 300-page hardcover at $24.99 earns: $14.99 − $10.40 = $4.59. Lower than paperback, but adds a premium-tier option some readers actively prefer. See our paperback vs hardcover deep-dive for the full ROI breakdown.

The Kindle Unlimited formula

KU pays roughly $0.0040–$0.0048 per page read (KENPC count, not actual pages). A 300-page novel read fully = ~$1.30 per read-through. A 500-page LitRPG read fully = ~$2.20. KU rewards length and series binge-reads — see our KU strategy guide for the full optimization playbook.

Realistic per-book earnings curves (2026)

1. Single AI-assisted ebook, no ads, no series: $20–$80/month for the first 6 months, then decay to $5–$15/month.
2. Single book + paperback + light Amazon ads: $150–$400/month sustained.
3. 5-book series in KU with read-through: $800–$3,000/month sustained.
4. 10+ book series with active ads and series branding: $5K–$20K/month sustained.

The pricing decisions that matter most

1. Stay inside the 70% band. Every ebook should be priced between $2.99 and $9.99 unless you have a specific reason. The 35% tier is brutal.
2. Match price to genre expectations. Romance: $3.99–$4.99. Cozy mystery: $4.99–$5.99. Non-fiction: $7.99–$14.99. LitRPG: $4.99–$6.99. Mispricing is the #1 self-inflicted sales killer.
3. Use page count as a lever, not a default. KU rewards long; paperback rewards short; ebook is neutral. Optimize per format.
4. Stack formats. Same book in ebook + paperback + KU + audiobook can 3–4× per-title revenue with no additional writing.

The single mental model that beats every calculator

Per-book royalty matters less than catalog read-through. A $3.94 paperback that's book one of a five-book series is worth far more than a $7.79 standalone — because every reader who finishes book one buys two more. Build catalogs that compound, not standalones that peak.

Bottom line

Pin these formulas to your wall: ebook = (price × 0.70) − $0.06; paperback = (price × 0.60) − ($0.85 + $0.012/page); KU ≈ $0.0044/page. Then stop optimizing per-book royalty in isolation and start optimizing catalog-level read-through. That's the math that turns a hobby into a $5K/month KDP business.