varunk130 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
- Keep context files updated
- Be conservative - optimistic estimates lose credibility
- Show your work - transparent assumptions > black box
- Multiple approaches - if they diverge, you're missing something