Market Size & Opportunity Estimator
Estimate your total addressable market (TAM), serviceable market (SAM), and obtainable market (SOM) using a bottoms-up approach. Produces investor-ready market sizing with documented assumptions and multiple estimation methods for cross-validation.
market size · TAM SAM SOM · opportunity · market research · investor · business plan · strategy
Start with the narrowest, most defensible number you can: your SOM. Investors and partners respect bottoms-up math from real data points more than inflated top-down TAM claims.
How to use this prompt
- Pick your AI model. Choose the tab for Claude, ChatGPT, Gemini or Copilot. Each variant is tuned for that model.
- Copy the full prompt. Click Copy Full Prompt to copy the text to your clipboard.
- Paste into your AI tool. Open your chosen model and paste the prompt into a new chat.
- Replace the [placeholders]. Swap any bracketed fields for your company name, audience, product or tone.
- Run and refine. Review the output. If anything is off, ask the AI to tighten tone, length or format.
Prompt Variants by Model
Act as a market research analyst. Build a market sizing model.
Product [WHAT] · price [AMOUNT] · target [WHO — role, company size, industry, geography] · current customers [NUMBER] · current revenue [AMOUNT] · geography [local / national / global]
Deliver:
1. Top-down estimate with each filter documented
2. Bottom-up estimate with the math shown
3. TAM / SAM / SOM with clear definitions
4. Assumptions table with a confidence level per assumption
5. Sensitivity analysis — ±30% on the core assumptions
6. Comparable benchmarks
7. Investor-ready one-paragraph summary
Success means the top-down and bottom-up estimates are reconciled (explain any gap), and every number that isn't mine is labeled as an assumption with its source or reasoning.
Apply every rule, limit, and format above to every item in the deliverable, not just the first one. Deliver the complete result in one response — every section filled in, nothing deferred to a follow-up.
If a required input is missing, ask for it once before starting; otherwise proceed and label any assumption you made.Notes: R40 refresh; tuned to vendor prompting guidance
Frequently Asked Questions
What does the Market Size & Opportunity Estimator prompt do?
Estimate your total addressable market (TAM), serviceable market (SAM), and obtainable market (SOM) using a bottoms-up approach. Produces investor-ready market sizing with documented assumptions and multiple estimation methods for cross-validation.
Which AI models is this prompt written for?
Claude, ChatGPT, Gemini and Copilot. Each one gets its own version up top, written the way that vendor says to prompt its own model. Pick the tab that matches yours.
Do I need a paid AI account to use this prompt?
No. This prompt is written to run on the free tier of Claude, ChatGPT, Gemini and Copilot. Paid tiers simply give you longer context windows and faster responses.
Can I customize this prompt for my business?
Yes. Any text inside square brackets is a placeholder you replace with your own business details, such as company name, audience, product or tone. You can also ask the AI to adjust format, length or style after the first output.
When was this prompt last checked?
The date is on each version up top. We check every prompt in full every month, and when a major new model lands we rewrite the prompt for it. One glance tells you how current it is before you paste.
Works with
More in Competitor & Market Research
Competitor Deep Dive Analysis
Conduct a thorough competitor analysis: positioning, pricing, strengths, weaknesses, customer…
Customer Persona Builder
Build detailed customer personas from your existing data: purchase history, support conversations,…
Industry Trend Briefing
Generate a concise, actionable briefing on the trends shaping your industry: what is changing, why…