SOM
Also: SOM, Serviceable Obtainable Market, Serviceable Obtainable Marché, Marché Réellement Accessible, Share of Market, Obtainable Market
Serviceable Obtainable Market: the share of your SAM you can realistically capture given current resources, channels, and competitive position.
What It Is
SOM (Serviceable Obtainable Market) is the portion of your Serviceable Available Market (SAM) that you can realistically win in a defined time frame, given your actual resources, distribution, brand, and competitive position. It is the most conservative and most operational figure in the classic market sizing trio:
- TAM (Total Addressable Market): total demand if you had 100% market share.
- SAM (Serviceable Available Market): the slice of TAM your product, geography, and business model can actually serve.
- SOM (Serviceable Obtainable Market): the slice of SAM you can capture in practice, usually expressed as revenue or number of customers over a period (for example, 12 to 36 months).
Why it matters
TAM impresses investors, but SOM is what teams are actually held accountable for. It converts an abstract opportunity into a credible, resource-bound target.
- It grounds revenue forecasts and hiring plans in reality.
- It exposes whether a growth plan is ambitious or delusional.
- It aligns finance, marketing, and product on a shared, defensible number.
A SOM that equals your SAM signals magical thinking. A SOM near zero signals a weak position or a market not worth entering.
How it is used in practice
There are two common estimation approaches:
- Top-down: apply a realistic market share percentage to SAM, benchmarked against competitors and your channel reach.
- Bottom-up: build from unit economics (leads, conversion rates, sales capacity, average contract value) and sum to a total. This is generally more defensible.
Key inputs to pressure test:
- Sales and marketing capacity (headcount, budget, pipeline).
- Conversion and win rates from real data.
- Competitive intensity and switching costs.
- Time horizon and ramp assumptions.
Worked Example
A company sells a data governance platform.
- TAM: all organizations needing data governance globally, worth 10 billion USD.
- SAM: mid-market firms in Europe using a specific cloud stack, worth 800 million USD.
- SOM: with a 15-person sales team, current pipeline, and a 4% realistic 24-month share, the obtainable market is 32 million USD (4% of 800 million).
Bottom-up check: 300 qualified leads per year, 20% win rate, 50,000 USD average contract, over two years gives roughly 6 million USD in new annual recurring revenue, which recalibrates the share assumption downward. The gap between the two methods is the signal: reconcile it before committing to targets.
See also
Frequently asked questions
What does SOM stand for and how is it different from TAM and SAM?
SOM means Serviceable Obtainable Market: the share of your SAM you can realistically win in a defined period, given your resources, channels, brand, and competitive position. TAM is total demand if you held 100% share; SAM is the slice of TAM your product, geography, and business model can actually serve. SOM is the most conservative of the three, and the only one a team is genuinely accountable for.
Why do investors ask about TAM while operating teams work on SOM?
TAM sells the size of the opportunity; SOM sets the target people are measured against. The Serviceable Obtainable Market turns an abstract market into a resource-bound number that grounds revenue forecasts and hiring plans, and it aligns finance, marketing, and product on a figure they can defend.
How do you actually calculate SOM?
Two approaches. Top-down: apply a realistic market share percentage to your SAM, benchmarked against competitors and your channel reach. Bottom-up: build from unit economics such as leads, conversion and win rates, sales capacity, and average contract value, then sum over the period. The bottom-up version is generally more defensible because every assumption is traceable to real data.
What signals that a SOM estimate is not credible?
A SOM close to your SAM signals magical thinking: it assumes you can serve the entire addressable slice with the resources you have. A SOM close to zero signals a weak competitive position or a market not worth entering. Between those extremes, pressure test sales and marketing capacity, conversion and win rates from real data, competitive intensity and switching costs, and the ramp assumptions behind your time horizon.
What do you do when top-down and bottom-up SOM give very different numbers?
Reconcile the gap before committing to any target: the difference is the signal, not a rounding error. Example from a data governance platform with a 10 billion USD TAM and an 800 million USD SAM: a 4% share over 24 months gives a top-down SOM of 32 million USD, while the bottom-up build (300 qualified leads a year, 20% win rate, 50,000 USD average contract, over two years) yields roughly 6 million USD. That gap means the share assumption was too optimistic and should be recalibrated downward.