> ## Content Index
> Fetch the complete content index at: https://buildwire.ai/llms.txt
> Use this file to discover other available public pages before exploring further.

# Market Sizing Calculator
- URL: https://buildwire.ai/claude-skills/market-sizing-calculator/
- Published: 2026-09-04T04:59:46.000Z
- Updated: 2026-09-04T05:01:43.000Z
- Description: Estimate TAM SAM and SOM using top-down and bottom-up methods with explicit assumptions and source notes.
- Author: BuildWire AI
- Tags: Strategy, #buildwire-claude-resource, #buildwire-skill

Free Claude Skill

# Market Sizing Calculator

Estimate TAM SAM and SOM using top-down and bottom-up methods with explicit assumptions and source notes.

[Download Skill \->](https://buildwire.ai/assets/resources/claude-skills/market-sizing-calculator.skill)[Browse all Skills](https://buildwire.ai/claude-skills/)

## What this Skill helps with

Estimate total, serviceable, and obtainable market size using top-down and bottom-up methods with explicit assumptions and source notes.

## Who this Skill is for

This Skill is intended for founders, product teams, and marketers who need a transparent market-size estimate for planning, fundraising, or opportunity comparison. It is most useful when the team can supply credible market data, pricing, customer counts, geography, and delivery constraints.

## What you provide

- The product or service being sized and the target customer
- Relevant geography, industry, and time period
- Pricing, expected annual value, or transaction assumptions
- Credible reports, customer counts, or company data with source dates
- Constraints that separate the total market from the reachable market

## What it produces

- Separate TAM, SAM, and SOM estimates
- Top-down and bottom-up calculations where the inputs allow both
- A table of assumptions, sources, ranges, and missing evidence
- Sensitivity cases showing which inputs change the estimate most
- Questions to resolve before the estimate is used externally

## How to use it

1. Download the Skill file and add it to Claude.
2. Describe the offer, customer, geography, and purpose of the estimate.
3. Provide the available market evidence, pricing, and operating constraints.
4. Ask for more than one method and require each assumption to be shown.
5. Review the sources and calculations before using the result.

## Example workflow

Estimate the market for a B2B reporting product sold to mid-sized agencies in India. Provide the estimated agency count, expected annual contract value, target regions, and the percentage the sales team can realistically reach. Compare a customer-count calculation with a published market report and explain why the two results differ.

## Limits and review guidance

Market-size estimates are highly sensitive to definitions and assumptions. A broad industry report may include customers, regions, or products that are not relevant to the offer. Confirm source dates, avoid unsupported precision, and present a range when the evidence does not support one exact figure.

## Frequently asked questions

### What is the Market Sizing Calculator Skill?

It is a downloadable Claude Skill for estimating total, serviceable, and obtainable markets while keeping the assumptions and source evidence visible.

### What do I need before I run it?

Prepare a clear customer definition, geography, pricing or annual value, available market reports, customer-count evidence, and practical limits on who the business can serve.

### Does the Skill make changes automatically?

No. It produces a result for review. Any change to a live account, campaign, website, or customer workflow still needs separate approval.

### Is the result suitable for an investor deck?

It can provide a documented starting point. Check the source rights, calculations, dates, definitions, and assumptions before presenting the estimate to investors or other external audiences.

## Included in these packages

[**Founder, Product & Research Skills Pack**8 Claude skills for go-to-market strategy, product questions, market research, pitch decks, investor material, and pricing.](https://buildwire.ai/claude-skills/founder-product-and-research-skills-pack/)

## Related Skills

[**Campaign Strategy & Planning**Turn campaign goals into positioning, channels, KPIs, budget logic, and a practical launch plan.](https://buildwire.ai/claude-skills/campaign-strategy-and-planning/)[**Pricing Strategy Optimizer**Compare competitor pricing, value framing, and buyer behavior to produce a recommendation memo.](https://buildwire.ai/claude-skills/pricing-strategy-optimizer/)[**Idea Validator**Test a campaign or product concept against desirability, feasibility, and viability with a go-or-no-go scorecard.](https://buildwire.ai/claude-skills/idea-validator/)

**Published by BuildWire AI.** Reviewed on 2026-09-03.