/tam-sam-som-calculator

name: tam-sam-som-calculator
description: Calculate TAM, SAM, and SOM with explicit assumptions, methods, and caveats. Use when sizing a market for a product idea, business case, or executive review.
intent: >-
  Guide product managers through calculating Total Addressable Market (TAM), Serviceable Available Market (SAM), and Serviceable Obtainable Market (SOM) for a product idea by asking adaptive, contextually relevant questions. Use this to build defensible market size estimates backed by real-world citations, economic projections, and population data—essential for pitching to investors, securing budget, or validating product-market fit.
type: interactive

Purpose

Guide product managers through calculating Total Addressable Market (TAM), Serviceable Available Market (SAM), and Serviceable Obtainable Market (SOM) for a product idea by asking adaptive, contextually relevant questions. Use this to build defensible market size estimates backed by real-world citations, economic projections, and population data—essential for pitching to investors, securing budget, or validating product-market fit.

This is not a back-of-napkin guess—it's a structured, citation-backed analysis that withstands scrutiny.

Key Concepts

TAM/SAM/SOM Framework

The three-tier market sizing model:

**Total Addressable Market (TAM):**

• The total market demand for a product or service
• "If we captured 100% of the market, what's the revenue?"
• Broadest possible market (no constraints)

**Serviceable Available Market (SAM):**

• The segment of TAM your company can realistically target
• Narrowed by geography, firmographics, demographics, or product constraints
• "Who can we actually reach with our product?"

**Serviceable Obtainable Market (SOM):**

• The portion of SAM you can realistically capture
• Accounts for competition, market constraints, go-to-market capacity
• "What can we capture in the next 1-3 years?"

Why This Works

• **Top-down validation:** TAM → SAM → SOM ensures estimates are grounded in reality
• **Investor-friendly:** Standard framework VCs and execs understand
• **Citation-backed:** Real data sources (Census, Statista, World Bank) add credibility
• **Adaptive:** Questions adjust based on context (B2B vs. B2C, US vs. global, etc.)

Anti-Patterns (What This Is NOT)

• **Not a single-number guess:** "The market is $10B" without supporting data
• **Not static:** Markets evolve—reassess annually
• **Not a substitute for customer validation:** Market size ≠ product-market fit

When to Use This

• Pitching to investors or execs (need market size in deck)
• Validating product ideas (is the market big enough?)
• Prioritizing product lines (which has bigger opportunity?)
• Setting growth targets (what's realistic to capture?)

When NOT to Use This

• For internal tools with captive users (no external market)
• Before defining the problem (market sizing requires clear problem space)
• As the only validation (pair with customer research)

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Facilitation Source of Truth

Use [`workshop-facilitation`](../workshop-facilitation/SKILL.md) as the default interaction protocol for this skill.

It defines:

• session heads-up + entry mode (Guided, Context dump, Best guess)
• one-question turns with plain-language prompts
• progress labels (for example, Context Qx/8 and Scoring Qx/5)
• interruption handling and pause/resume behavior
• numbered recommendations at decision points
• quick-select numbered response options for regular questions (include `Other (specify)` when useful)

This file defines the domain-specific assessment content. If there is a conflict, follow this file's domain logic.

Application

Use `template.md` for the full fill-in structure.

This interactive skill asks **up to 4 adaptive questions**, offering **enumerated context-aware options** at each step. The agent adapts questions based on previous responses.

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Step 0: Gather Context (Before Questions)

**Agent suggests:**

Before we begin, it's helpful to have product context. If available, please share:

**For Your Own Product:**

• Website copy (homepage, product pages, value prop statements)
• Marketing emails or landing pages
• Product descriptions or positioning statements
• Case studies or customer testimonials
• Sales deck or pitch materials

**If You Don't Have a Product Yet:**

• Find a similar or adjacent product (competitor or analog)
• Copy their website homepage, product description, or landing page
• We'll use this as a reference point for market sizing

**You can paste this content directly, or we can proceed with a brief description.**

**Why this helps:**

• Marketing materials already contain target audience, pain points, and value props
• Analyzing real content (yours or competitors') grounds the analysis in reality
• You can benchmark against similar products' market positioning

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Optional Helper Script (Deterministic Math)

If you already have population and ARPU numbers (or a TAM estimate), you can run a deterministic helper to compute TAM/SAM/SOM and generate a Markdown table. This script does **not** fetch data or write files.

python3 scripts/market-sizing.py --population 5400000 --arpu 1000 --sam-share 30% --som-share 10%

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Question 1: Problem Space

**Agent asks:** "Based on the context you've provided (or will describe), what problem space are you exploring for market sizing?"

**Offer 4 enumerated examples (user can select by number or write custom):**

1. **B2B SaaS productivity** — E.g., "Workflow automation for small business operations" (like Zapier, Integromat) 2. **Consumer fintech** — E.g., "Personal budgeting app for Gen Z users" (like Mint, YNAB) 3. **Healthcare/telehealth** — E.g., "Mental health support for remote workers" (like BetterHelp, Talkspace) 4. **E-commerce enablement** — E.g., "Payment processing for online sellers" (like Stripe, Square)

**Or write your own problem space description based on the marketing materials you share