TAM, SAM, and SOM for founders

Last updated 2026-07-27

TAM, SAM, and SOM explained for founders: size your market with editable assumptions, provenance, and fact-check support in Mira’s market model.

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Definitions

TAM (Total Addressable Market), the broad revenue opportunity if every potential customer bought.

SAM (Serviceable Addressable Market), the segment you can realistically reach with your product, geography, and channels.

SOM (Serviceable Obtainable Market), near-term capturable share given competition, capacity, and go-to-market reality.

Collapsing these into one slide number is a common pitch mistake. A $1,000,000,000 TAM is not a $10,000,000 SOM: that can be a 100× gap.

How Mira helps you size the market

Mira’s market model produces TAM → SAM → SOM with editable levers, assumption provenance, and optional fact-check against research. You can stress-test bull / base / bear scenarios instead of locking a single vanity figure into a deck.

Pair market sizing with competitor matrices so SOM reflects real rivals, not a vacuum.

Practical tip

Write the market definition first (category + geography + buyer), then attach numbers. Mira pins that definition so sizing and fact-check stay aligned. See /methodology for how estimates are graded.

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