Pro Author · Built for indie authors

Book Royalty Calculator — Profit, Breakeven & Per-Book Margin

Calculate per-book profit, breakeven units, and royalty margin for self-published books before you invest in editing, cover, and marketing. The numbers every Pro Author needs before launch.

What readers pay — list price, not list minus promo.
Realistic 12-month forecast, not best-case.
Amazon KDP print = 70%. KDP ebook 35–70%. Draft2Digital 90%.
Developmental, line, or copy editing — total one-time cost.
Custom cover design or premium premade.
Ads, promos, ARC, review copies — launch + first 90 days.
Per-book margin
$2.49
net per copy sold
Estimated profit
$2,493
over expected sales
Breakeven units
232
covers fixed costs
Breakdown
Total revenue $4,990
Royalty × units $3,493
Fixed costs (editing + cover) $700
Marketing spend $300

How the math works

Per-book margin is the royalty split (price × royalty%) minus any per-copy variable costs you incur — for most indie authors it's just the royalty itself, so this is the cleanest read on what each copy puts in your pocket.

Estimated profit is total royalty income across your expected unit sales minus fixed (editing + cover) and variable (marketing) costs. This is the line item investors and your accountant actually care about.

Breakeven units is the number of copies you need to sell for total royalty income to equal your fixed costs. Marketing spend is treated separately because it scales with how aggressively you launch — it's a return-on-ad-spend number more than a true cost of goods.

Email me the full worksheet

Get the editable Profit Calculator worksheet (Google Sheets + PDF) with pricing-tier scenarios, sensitivity analysis, and breakeven formulas — straight to your inbox.

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