Framework
Term

TAM / SAM / SOM

Three nested market-sizing figures: Total Addressable Market (the whole opportunity), Serviceable Addressable Market (the slice your offering can reach), and Serviceable Obtainable Market (the slice you can realistically win in the near term).

TAM / SAM / SOM is the standard market-sizing framework used in startup pitch decks, strategic planning, and category analysis. Each layer is a nested subset of the one above it.

TAM — Total Addressable Market

The total revenue opportunity if a single product served every potential customer worldwide. Example: for a payroll software, TAM might be "all global businesses with at least one employee × average payroll software ARPU". TAM is necessarily a top-down estimate and should be defended with credible third-party data (industry reports, government statistics).

SAM — Serviceable Addressable Market

The portion of TAM that your specific offering could reach given language, geography, regulatory, and channel constraints. A US-only payroll product can't serve EU businesses, so its SAM excludes them. SAM is typically 5–30% of TAM for early-stage products and grows toward TAM over years as the product expands.

SOM — Serviceable Obtainable Market

The realistic slice of SAM you can capture in the near term (typically 3–5 years), given competition, your distribution capacity, and your unit economics. SOM is the most-disputed number — it's where pitch decks make optimistic assumptions and where investors push back. A defensible SOM cites a similar-stage competitor's actual penetration of the same SAM.

What good TAM/SAM/SOM looks like

The pattern most VCs accept:

  • TAM: $10B+ — large enough to support a unicorn outcome
  • SAM: 10–30% of TAM
  • SOM: 1–10% of SAM (capturable in 3–5 years)

Inflated TAM (combining unrelated categories) is the most common pitch-deck failure. The honest test: would a customer in your TAM actually pay for your product, not a product in your general category?

Related

  • ICP — the customer profile that defines who is in SOM
  • Positioning — how you communicate where in SAM you sit
  • Blue Ocean — strategy for creating new TAM rather than dividing existing TAM

See also

Nearby terms

All terms →
Segmentation

The practice of dividing a market into groups that share buying behavior, needs, or willingness to pay. Useful segmentation produces groups large enough to matter and homogeneous enough to act on differently.

SWOT

A 2×2 strategy framework that maps a position across four dimensions: internal Strengths and Weaknesses (what the team controls) and external Opportunities and Threats (what the market is doing around it). Developed by Albert Humphrey at Stanford in the 1960s.

Time to Value (TTV)

The time between a customer signing up for a product and experiencing its first meaningful value. Short TTV correlates strongly with retention; long TTV correlates with churn before users ever see what the product can do.

Unit Economics

The revenue and cost associated with a single 'unit' of a business — typically one customer or one transaction. The fundamental test of whether a business model can ever be profitable.