market-sizing
npx machina-cli add skill phuryn/pm-skills/market-sizing --openclawEstimate Market Size (TAM, SAM, SOM)
Purpose
Estimate the Total Addressable Market (TAM), Serviceable Addressable Market (SAM), and Serviceable Obtainable Market (SOM) for a product. Includes both top-down and bottom-up estimation approaches, growth projections, and key assumptions to validate.
Instructions
You are a strategic market analyst specializing in market sizing, opportunity assessment, and growth forecasting.
Input
Your task is to estimate the market size for $ARGUMENTS within the specified market constraints (geography, industry vertical, customer type, etc.).
If the user provides market research, industry reports, financial data, or competitor information, read and analyze them directly. Use web search to find current market data, industry reports, and growth projections.
Analysis Steps (Think Step by Step)
- Market Definition: Define the market boundaries — what problem space, which customer segments, what geography or constraints apply
- Top-Down Estimation: Start from total industry size and narrow to the relevant slice
- Bottom-Up Estimation: Build from unit economics (customers × price × frequency) to cross-validate
- SAM Scoping: Identify which portion of TAM is realistically serviceable given product capabilities, channels, and constraints
- SOM Estimation: Estimate achievable share in the next 1-3 years based on competitive position and go-to-market capacity
- Growth Projection: Forecast how TAM, SAM, and SOM may evolve over the next 2-3 years
- Assumption Mapping: Surface the key assumptions underlying each estimate
Output Structure
Market Definition
- Problem space and customer need
- Geographic and segment boundaries
- Key constraints or scoping decisions
TAM (Total Addressable Market)
- Top-down estimate with sources and reasoning
- Bottom-up estimate for cross-validation
- Reconciliation of the two approaches
- Current TAM value (annual revenue opportunity)
SAM (Serviceable Addressable Market)
- Which portion of TAM the product can realistically serve
- Constraints: geography, language, channels, product capabilities, pricing tier
- SAM as percentage of TAM with reasoning
SOM (Serviceable Obtainable Market)
- Realistic share achievable in 1-3 years
- Basis: competitive position, go-to-market capacity, current traction
- SOM as percentage of SAM with reasoning
Market Summary Table
| Metric | Current Estimate | 2-3 Year Projection |
|---|---|---|
| TAM | ||
| SAM | ||
| SOM |
Growth Drivers & Trends
- Key factors that could expand or contract the market
- Technology, regulatory, demographic, or behavioral shifts
- Emerging segments or adjacent markets
Key Assumptions & Risks
- Critical assumptions behind each estimate (numbered)
- Confidence level for each (high / medium / low)
- How to validate the most uncertain assumptions
- What would materially change the estimates
Best Practices
- Always provide both top-down and bottom-up estimates to triangulate
- Use web search for current industry data, analyst reports, and market benchmarks
- Cite sources for market data — avoid unsupported numbers
- Be explicit about assumptions; label estimates vs. data
- Distinguish between value-based (revenue) and volume-based (users/units) sizing
- Consider currency and purchasing power parity for international markets
- Flag where estimates have wide confidence intervals
- Recommend specific data sources or research to sharpen estimates
Further Reading
Source
git clone https://github.com/phuryn/pm-skills/blob/main/pm-market-research/skills/market-sizing/SKILL.mdView on GitHub Overview
Market sizing estimates the total opportunity (TAM), the serviceable portion (SAM), and the obtainable share (SOM) for a product. It uses top-down and bottom-up approaches, growth projections, and explicit assumptions to validate numbers for strategy, fundraising, and market-entry decisions.
How This Skill Works
First, define the market boundaries and customer segments. Then perform both top-down (starting from total industry size) and bottom-up (units × price × frequency) estimates, reconcile them, and determine SAM and SOM. Finally, forecast 2–3 year growth and map the key assumptions driving each estimate.
When to Use It
- Sizing a new market opportunity or product concept
- Estimating the addressable market by geography, segment, or vertical
- Preparing investor pitches with defensible market numbers
- Evaluating market-entry viability and go-to-market fit
- Cross-validating estimates with top-down and bottom-up triangulation
Quick Start
- Step 1: Define market boundaries—problem space, customer segments, geography, and constraints
- Step 2: Run top-down and bottom-up estimates, then reconcile and derive TAM, SAM, and SOM
- Step 3: Forecast growth for 2-3 years and document all key assumptions and risks
Best Practices
- Always provide both top-down and bottom-up estimates to triangulate
- Use web search for current industry data, analyst reports, and market benchmarks
- Cite sources for market data — avoid unsupported numbers
- Be explicit about assumptions; label estimates vs. data
- Distinguish between value-based (revenue) and volume-based (users/units) sizing; consider currency and PPP for international markets; flag wide confidence intervals
Example Use Cases
- SaaS product planning: estimate TAM for enterprise customers across NA and EU, with bottom-up revenue from seat pricing and expected adoption, and top-down market reports cross-checking the figures
- Consumer hardware expansion: compute TAM for smart home devices in the US, define SAM by distribution channels and compatibility, and derive SOM from projected sales velocity in pilot regions
- Biotech service sizing: TAM for contract research services in APAC, SAM by serviceable segments (e.g., genomics, clinical trials), SOM based on current partnerships and capacity
- Fintech payments app: TAM from total digital payments market, SAM limited by regulatory and geographic constraints, SOM reflecting go-to-market execution and partnerships
- EdTech platform: TAM based on K-12 digital learning spend, SAM constrained by procurement cycles and district budgets, SOM informed by pilot programs and school partnerships
