Tam Sam Som Calculator

If you've ever been asked "how big is the market?" and scrambled to defend a number, this walks you through TAM/SAM/SOM with citations instead of guesses. It adapts questions based on whether you're sizing B2B SaaS, consumer fintech, or healthcare, and adjusts for geography (US Census data hits different than global estimates). You can paste competitor marketing copy if you don't have your own yet. The output is investor-ready because it shows assumptions and data sources, not just a slide with "$10B market" on it. Pairs with the workshop-facilitation protocol, so expect numbered options and step-by-step prompts rather than a wall of text.

skills.sh installs: 2.3K
GitHub stars: 7.9K
last updated: Aug 21, 2026

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Install

$ npx -y skills add deanpeters/product-manager-skills --skill tam-sam-som-calculator --agent claude-code

Installs into .claude/skills of the current project.

Files

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.

Input

Works best with: The product or idea being sized, and any market constraints you already know (geography, vertical, customer type). Also useful: Pricing assumptions, comparable companies, and the audience for the numbers (investors, execs, business case).

Anything supplied with the invocation itself — text after the skill name, a pasted context dump, or an appended ARGUMENTS: line — counts as answers already given. Use it and skip whatever it covers; don't re-ask.

Arriving empty-handed? That works too. The calculator opens by asking what you're sizing and for whom, then works through method and assumptions.

SKILL.md on GitHub