Best thing to validate
Self-published authors often fumble with print specs, leading to rejected files
Opportunity report AI draft report Trending eval Listed publicly
Readable in one screen · decide continue or stop first
ConceptA trim size and margin calculator for self-published books
Do self-published authors actually struggle with choosing tr
Core takeaway / TL;DR
No traceable demand evidence yet. Try first: Run a one-week landing page test: b
Suggested next step Run a one-week landing page test: build a static page with a
No traceable demand evidence yet. Try first: Run a one-week landing page test: b
Biggest risk
The problem may be too small: authors might use free templates or the built-in c
Critical assumption (summary)
Self-published authors find the current process of choosing trim size and margins confusing enough to seek a dedicated t
Show objections and continue/stop
Strongest objection
Most authors use free templates from KDP or IngramSpark, or they simply follow a guide. A calculator may be redundant.
Continue if
If sign-ups show clear pain, build the MVP calculator and test a paid version (e.g., $5 one-time) with a small group.
Pivot if
If no sign-ups or interviews reveal that the problem is already solved by existing free tools, pivot to a broader format
Show score rationale
We could use AI to generate margin recommendations based on historical print specifications, but this is not required for an MVP.,A visual preview could be generated with a simple HTML/CSS mockup, not AI.
Fill the critical gaps (max 2)
“I don’t know” is fine — we give how to get evidence; we never invent interviews or payments.
02 Where the signal came from
Search interest 03 Search trend evidence
Is anyone searching? Relative interest — not monthly volume.
Trends 0–100 is relative interest, not monthly volume; 0 ≠ no demand.
Trends unchecked
Live search interest not checked yet. Conclusions below are hypotheses pending validation.
04 Business breakdown
Who needs this
Self-published authors who are preparing a print edition (e.g., via KDP or IngramSpark) and are not using a professional formatter.
Job to be done
Quickly determine the correct trim size and margin settings for a book to avoid print rejection and excessive page count (which raises printing costs).
Why they might pay
To save time and avoid costly mistakes; a one-time fee is acceptable if the tool is reliable and visually clear.
Alternatives
Free templates from KDP/IngramSpark, Word/Google Docs templates, online guides, hiring a formatter (expensive), or trial-and-error.
Differentiation wedge
A simple calculator that outputs exact margin values and a visual preview of a page with text, based on book type and page count. Later, add cover spine calculation or export a PDF spec sheet.
OPC scope
MVP scope: a static calculator that takes book type, page count, binding, and returns recommended trim sizes and margin values with a simple preview image. No user accounts, no payment processing initially.
Open questions
- Which binding types matter most (perfect bound, saddle stitch, hardcover)?
- Do authors want recommendations for specific platforms (KDP vs IngramSpark) or generic?
- Is there a segment (e.g., fiction vs non-fiction) that has more pain?
- Would they prefer a one-time payment or a subscription for ongoing updates?
05 Search & acquisition
Primary channel:
Self-publishing communities on Reddit (r/selfpublish, r/writing), KDP forums, Facebook groups, and Google Ads on high-intent keywords.
Click a keyword to copy. Tags: AI candidate / queried / thin sample.
Talking points
- Avoid file rejection from KDP/IngramSpark
- Save money on printing costs by optimizing page count
- Get print-ready specs in 30 seconds
- Visual preview so you see exactly how your page will look
Minimum experiment 06 Minimum validation experiment
One falsifiable step before you continue or stop.
Valid signal = real task completion, reuse, or pay intent — with observe + continue/stop.
Build a landing page with a mock calculator: a form asking for book type, page count, and binding, then showing a sample output (trim size and margins) with a static preview image. No real calculation behind it.
Add an email capture form for a free version and a 'Pre-order Pro for $5' button (without payment processing, just a waitlist).
Post the landing page link in 3–5 self-publishing communities (Reddit, Facebook groups) with a question about their current formatting process.
FAQ
Should I keep building this idea?
No traceable demand evidence yet. Try first: Run a one-week landing page test: b
What is the smallest next experiment?
Run a one-week landing page test: build a static page with a
What is the biggest risk right now?
The problem may be too small: authors might use free templates or the built-in c
Who is this validation for?
Self-published authors who are preparing a print edition (e.g., via KDP or IngramSpark) and are not using a professional formatter.
How should I read the score?
Current OPC feasibility score is 5/100. It is an AI-assisted executability check, not a market guarantee. Low scores mean “prove demand first,” not “never build.”
07 Evidence & boundaries
Demand evidence summary
No traceable external evidence yet. The model hypothesis is plausible but must be tested with a landing page or interviews.
External record
None
User-stated
None
Model hypothesis
- Self-published authors often search for 'book trim size calculator' or 'margin calculator for KDP' when preparing their manuscript.
- They may struggle with understanding inside/outside margins for page counts and binding types.
- A tool that prevents file rejection could save hours of back-and-forth with print platforms.
Known facts
- Self-published authors must specify trim size and margins when submitting print files to platforms like KDP or IngramSpark.
- Incorrect margins can cause text to be cut off or lead to file rejection.
- Standard trim sizes exist (e.g., 6x9, 5x8) and margin guidelines vary by page count and binding.
- Authors often use free templates provided by platforms or word processors.
Unverified assumptions
- Some authors find the process of choosing trim size and margins confusing or time-consuming.
- A dedicated calculator would be more convenient than searching for templates.
- Authors might pay a small one-time fee for a tool that guarantees print-ready specs.
- The tool can be built quickly without complex algorithms.
AI inference: We could use AI to generate margin recommendations based on historical print specifications, but this is not required for an MVP.,A visual preview could be generated with a simple HTML/CSS mockup, not AI.
Share the judgment 08 Share
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