Market Sizing

Market Sizing Calculator

Calculate TAM/SAM/SOM using both top-down and bottom-up approaches with clear assumption tracking.

When to Use This Skill

• New product business cases
• Expansion into new markets or segments
• Investor/board presentations

What You'll Need

• Clear definition of your market boundaries
• Industry data or reports (for top-down)
• Unit economics inputs (for bottom-up)

Process

Step 1: Check Your Context

Read context files for company, product, personas, and competitor data.

Step 2: Define Market Boundaries

Define geography, customer segment, and use case boundaries.

Step 3: Top-Down Analysis

Start with total market and narrow down using industry reports and public filings.

Step 4: Bottom-Up Analysis

Build up from unit economics: potential customers x deal size x frequency.

Step 5: Triangulate

Compare approaches. Aligned = high confidence. Divergent = investigate.

Step 6: Document Assumptions

Every number gets a source or explicit assumption marker.

Framework Reference

TAM-SAM-SOM with dual methodology:

• Top-down: Market reports - narrow to segment
• Bottom-up: Unit economics - multiply out
• Triangulation increases confidence

Tips for Best Results

1. Keep context files updated
2. Be conservative - optimistic estimates lose credibility
3. Show your work - transparent assumptions > black box
4. Multiple approaches - if they diverge, you're missing something

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: varunk130
• Source: varunk130/claude-code-skills
• License: MIT

Install and usage instructions live in the source repository linked above.