# Estimate Market Size with TAM, SAM, and SOM

Market sizing is hard when sources, assumptions, and methods are scattered. This skill guides Claude, Codex, and Claude Code through defensible TAM, SAM, and SOM analysis.

## Install

```bash
npx skillstore add wshobson/market-sizing-analysis
```

## Metadata

- Status: approved
- Slug: wshobson-market-sizing-analysis
- Version: 1.0.0
- Author version: 1.0.0
- Skillstore revision: r1
- Version status: valid
- Tree hash: 616ee5f6116e860c9080353d56c6ce82d27d095e098511498aa8b398441f61ce
- Author: wshobson
- GitHub username: wshobson
- License: MIT
- Repository: https://github.com/wshobson/agents/tree/main/plugins/startup-business-analyst/skills/market-sizing-analysis/
- Ref: 36e07d5e13068e5be64447e8f20b427cf2cbd21a
- Supported tools: Claude, Codex, Claude Code
- Audit status: complete
- Agent install advisory: allowed
- Manual install advisory: allowed
- Artifact signature: available
- Audit attestation: unavailable
- Human verification: not\_verified
- Risk factors: external\_commands
- Quality score: 77
- Quality tier: bronze
- Public page: https://skillstore.pages.dev/skills/wshobson-market-sizing-analysis
- Manifest: https://skillstore.pages.dev/api/skills/wshobson-market-sizing-analysis/manifest

## Capabilities

- Explains TAM, SAM, and SOM definitions with practical examples.
- Provides top-down, bottom-up, and value-theory market sizing formulas.
- Guides source selection across industry reports, public data, filings, and customer research.
- Shows how to apply geographic, product, segment, and adoption filters.
- Includes investor and strategy presentation structures for market sizing work.
- Provides a complete SaaS market sizing example.

## Use Cases

- Prepare Investor Market Slides: Build a clear TAM, SAM, and SOM story with documented assumptions and conservative capture rates.
- Prioritize Market Segments: Compare customer segments by addressable revenue, serviceability, and realistic near-term opportunity.
- Validate Market Research Models: Check market sizing calculations against source quality, segment definitions, and triangulation logic.

## Prompt Templates

### Create a Basic Market Size

```
Estimate TAM, SAM, and SOM for my product: [product]. Target customers are [customer segment], geography is [region], and price is [price]. State assumptions clearly.
```

### Build a Bottom-Up Model

```
Use a bottom-up method to size [market]. Include customer segments, estimated customer counts, annual revenue per customer, penetration assumptions, and TAM, SAM, and SOM.
```

### Triangulate Multiple Methods

```
Size [market] using top-down, bottom-up, and value-theory methods. Compare results, explain differences, and recommend the most defensible range.
```

### Stress Test Investor Assumptions

```
Review this market sizing analysis: [paste analysis]. Find weak assumptions, missing sources, aggressive SOM claims, and changes needed for an investor presentation.
```

## Limitations

- Does not verify live market data without user-provided sources or browsing support.
- Requires assumptions about customer counts, pricing, and adoption rates.
- Cannot replace paid research reports or expert validation.
- Outputs depend on the quality and recency of source data.

## Best Practices

- Start with a precise market definition before calculating any market size.
- Use bottom-up analysis as the primary model when customer and pricing data are available.
- Document every source, assumption, filter, and capture rate.

## Anti Patterns

- Claiming the full global category as serviceable without geographic or product filters.
- Using one outdated report without triangulating against other sources.
- Projecting high SOM without evidence for distribution, resources, and competitive advantage.

## Security Audit

- Audited at: 2026-07-07T08:10:54.644\+00:00
- Summary: The flagged external command findings are Markdown code fences and inline file references used for formulas and resource paths, not executable shell usage. The reconnaissance findings are market research terms such as paid sources, distribution channels, go-to-market effectiveness, and common mistakes. No prompt injection or malicious intent was found in the cited files.

## Stats

- Views: 236
- Downloads: 15
- Favorites: 0
- Popularity score: 0