🎯 TAM SAM SOM Calculator
Size your market the way investors expect
TAM, SAM, and SOM Explained
These three figures define your market opportunity at decreasing levels of realism. TAM (Total Addressable Market) is the total revenue available if you captured 100% of your market with no competition or constraints. SAM (Serviceable Addressable Market) is the portion of TAM you can actually serve given your business model, geography, and regulatory reach. SOM (Serviceable Obtainable Market) is the share you can realistically capture in the near term, accounting for competition and your go-to-market capacity.
For a medical device company, TAM might be the global market for a treatment category, SAM might be the US market where you have regulatory clearance and a sales channel, and SOM might be the specific hospital systems or specialties you can realistically reach in your first 3-5 years. Investors use these numbers to judge whether the opportunity is large enough to justify a venture-scale return.
Top-Down vs Bottom-Up
Top-down starts from a published total market figure and narrows it with percentages. It is fast but can feel hand-wavy to sophisticated investors ("we just need 1% of a huge market" is a red flag). Bottom-up builds the market from the ground up: number of potential customers multiplied by revenue per customer. Bottom-up is more credible because it forces you to justify each assumption. The strongest pitch decks present both and show they roughly agree.
Frequently Asked Questions
What is a good SOM for a startup pitch?
There is no magic number, but your SOM should be defensible. Capturing 5-15% of your SAM within 3-5 years is often considered ambitious-but-credible. Claiming 50%+ of a market raises skepticism unless you have a clear monopoly dynamic.
Where do I find TAM data?
Industry reports (Grand View Research, MarketsandMarkets, IBISWorld), government health statistics, professional society data, and procedure-volume databases. For medtech, CMS reimbursement data and disease prevalence figures are valuable inputs.
Should I use revenue or unit volume?
Investors think in revenue, so express TAM/SAM/SOM in dollars. You can build them from unit volume (procedures, devices, patients) multiplied by price, which also makes your assumptions transparent.
Market sizing is an estimate built on assumptions. Use credible third-party data and document your methodology for investor due diligence.