TAM / SAM / SOM

Start here

What you get

It asks for the idea in a sentence or two first, then gathers only the inputs it doesn't have: who buys, pricing (revenue per customer), geography or segment, main competitors, any research the client has. If a Vertical IQ or industry report is uploaded, it pulls market size, pricing, and trends from it before asking. Then it works TAM → SAM → SOM in order, using top-down, bottom-up, or value-theory methods, and explains and validates each number.

Conversation skill. You start it by saying what you want; it asks for what it needs and hands back a deliverable in the same chat. Nothing to install beyond the plugin, nothing to configure.

What it never does

Never presents a number without the method and assumptions behind it.
Never skips the idea-in-a-sentence step — everything downstream depends on knowing what is sold to whom.

Step 2

Setting it up

Getting it on your side

The skill is plain instructions, so it runs wherever you already work. Pick your row:

Get the files: everything is in the public GitHub repository — the skills themselves, and the ready-to-install plugin file on the latest release. MIT licensed; no GitHub account needed to download.
Claude desktop app: download sbdc-toolkit.plugin from the latest release, drag it into a chat, click Accept.
ChatGPT: this skill is a plain Markdown file, not Claude-specific. Open skills/tam-sam-som/SKILL.md, copy the whole file, and paste it into a ChatGPT Project’s instructions or a custom GPT. Same instructions, same outputs.
Claude Code: /plugin marketplace add bwfnx/sbdc-toolkit then /plugin install sbdc-toolkit@maryland-sbdc

Your first conversation

Open a new chat and say:

Size the market for my client's [product] in Maryland.

It will ask for:

Whatever's missing from the input list; nothing it already has.

Step 3

How to use it

Say

Calculate TAM, SAM and SOM for this startup.How many customers can they realistically reach in year one?Turn this Vertical IQ report and pricing into market-size figures for the pitch deck.

What comes back

Three figures with the method, the inputs, and the assumptions each rests on — written so a client can defend them in a pitch or plan.

Then

Drop the figures into the business plan or deck; re-run when pricing or geography changes.

Tips from the field

Bottom-up (customers × price) is the number a lender or judge trusts; ask for it explicitly if the client only has top-down.