TAM is the total demand for a product, SAM is the part of it you can reach, and SOM is the part you can realistically win.
TAM SAM SOM means total addressable market, serviceable available market and serviceable obtainable market: a framework for sizing a market opportunity from the largest possible demand down to what you can realistically win. TAM is the total demand for a product if every potential customer bought it. SAM is the slice of that market you can actually reach given your product, geography, and go-to-market model. SOM is the share of SAM you can realistically capture in the near term. Investors size this both top-down and bottom-up to judge whether an opportunity is large enough to justify a venture-scale return.
By Pitchkit · Last Updated October 10, 2026
TAM, SAM and SOM stand for total addressable market, serviceable available market and serviceable obtainable market. TAM is every dollar of demand that would exist for your product if every potential buyer in the world purchased it. SAM narrows that down to the customers you can actually reach today, given your language, geography, product, and distribution. SOM narrows further still to the realistic share of SAM you can win within a specific timeframe, usually the next 3 to 5 years.
Investors read the three together as a funnel. TAM proves the ceiling is high enough to matter. SAM proves you have picked a reachable slice of that ceiling. SOM proves you have a credible, near-term plan to win part of that slice.
Venture investors need a market large enough that even a modest share of it can return their fund. TAM, SAM and SOM give them a structured way to test whether your opportunity clears that bar or whether you are chasing a market too small for the venture model.
Investors are especially skeptical of TAM numbers pulled from a single analyst report with no connection to your actual pricing or customer count. A credible bottom-up build carries far more weight than an impressive-sounding headline figure.
Your ICP is 120,000 SMBs that would pay €600 per year. TAM is 120,000 x €600 = €72 million. If you can reach 40,000 of them today, SAM is €24 million. If you can win 10 percent of SAM in 3 to 5 years, SOM is €2.4 million. Build the bottom-up number from customer counts and pricing, and use any top-down analyst figure only as a sanity check.
For the full step-by-step build, with bottom-up and top-down methods and ready-made inputs, use the free market size calculator linked below.
Most venture investors want to see a TAM of at least €1 billion and a SAM large enough to support a venture-scale outcome, often several hundred million euros. Niche markets with strong unit economics can still work for smaller funds or bootstrapped growth, but expect a harder conversation with traditional VCs.
SOM should connect directly to your go-to-market plan rather than being an arbitrary percentage. A realistic near-term SOM is often in the €10 million to €50 million range, though this varies enormously by market.
Using global search volume or a broad industry report number as TAM without connecting it to your actual pricing or customer count.
Setting an unrealistic SOM percentage, such as claiming you will capture 50 percent of SAM with no evidence of how.
Not matching pricing assumptions to the size and usage patterns of your actual ICP, which makes the whole calculation disconnected from reality.
On your market slide, show one clean bottom-up table with your sources and assumptions stated plainly, plus a brief note on expansion vectors, for example: Bottom-up: TAM €72 million, SAM €24 million, SOM €2.4 million at 10 percent of SAM.
Turn your metrics into a pitch narrative investors can follow.
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