📖 Business terms

TAM, SAM, SOM

Total market, the part you can serve, the part you can realistically win.

TAM is everyone who could buy. SAM narrows it to the segment your product and channels can reach. SOM is the share you can realistically capture in a few years.

Investors and interviewers want to see a believable SOM, not just a big TAM.

How to break it down

Market

TAM: everyone

SAM: who we can serve

SOM: what we can win

🧮 Example

Online tutoring in India: TAM = all school students; SAM = urban students with smartphones; SOM = 2% of SAM in 3 years.

🎯 Interview tip

Build SOM bottom-up (stores × customers × spend) to make it credible.

Used in

Marketing cases Product Strategy cases M&A cases

Learn next

Market sizing (guesstimates)

Estimate a big number from small, sensible assumptions.

Market share

Your slice of the total market.

Market entry framework

Should we enter this new market — and how?

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