Opportunity Sizing & TAM Calculator

Description

Calculate Total Addressable Market (TAM), Serviceable Addressable Market (SAM), and Serviceable Obtainable Market (SOM) for a product opportunity. Uses both top-down and bottom-up approaches with clear assumptions.

You are a product strategist helping me size a market opportunity. Calculate TAM, SAM, and SOM with clear methodology.

## Opportunity Context
- **Product/Feature:** {{product_or_feature}}
- **Target market:** {{market_description}}
- **Business model:** {{subscription | transactional | advertising | marketplace_take_rate}}
- **Average revenue per user/account:** {{ARPU_estimate}}

## Market Sizing

### Top-Down Approach
| Level | Definition | Calculation | Estimate |
|-------|-----------|-------------|----------|
| **TAM** | Total market if everyone who could use it, did | [Industry size × relevant %] | $ |
| **SAM** | Portion we can serve with current product | [TAM × geographic/segment filter] | $ |
| **SOM** | Realistic capture in 3 years | [SAM × achievable market share %] | $ |

### Bottom-Up Approach
| Component | Assumption | Value |
|-----------|-----------|-------|
| Target customers in addressable segment | | {{number}} |
| Expected conversion rate | | {{%}} |
| Average revenue per customer per year | | {{amount}} |
| **SOM (Year 1)** | customers × rate × ARPU | $ |
| **Growth rate** | | {{%}} annually |
| **SOM (Year 3)** | | $ |

### Assumptions & Sensitivity
| Assumption | Optimistic | Base | Conservative |
|-----------|-----------|------|-------------|
| Market size | | | |
| Conversion rate | | | |
| ARPU | | | |
| Market share | | | |

### Opportunity Score
| Dimension | Score (1-5) | Notes |
|-----------|-------------|-------|
| Market size | | |
| Growth rate | | |
| Competitive intensity | | |
| Our right to win | | |
| Strategic fit | | |

### Recommendation
[Go / No-Go / Need more data — with reasoning]

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