Total Addressable Market (TAM)

TAM is typically calculated using one of two approaches: top-down or bottom-up. The top-down approach starts with broad industry data from analyst reports and narrows it down to the relevant segment. The bottom-up approach starts with your unit economics, specifically the number of potential customers that match your ICP multiplied by your average annual contract value. The bottom-up method is generally more credible because it is grounded in your specific pricing and customer data rather than abstract industry estimates. TAM is usually discussed alongside two related metrics: SAM (Serviceable Addressable Market) and SOM (Serviceable Obtainable Market). SAM is the portion of TAM you can realistically reach with your current business model and geographic focus. SOM is the portion of SAM you can capture in the near term given your resources and competitive position. Investors care about TAM because it sets the ceiling on how large your company can become, but they evaluate your credibility based on how realistic your SAM and SOM estimates are. A TAM that is too small signals limited upside, while an unrealistically large TAM signals a lack of strategic clarity.

A compliance automation SaaS targets mid-market fintech companies in North America. There are approximately 4,000 fintech companies in the region with 50-1,000 employees. The product is priced at an average annual contract value of $36,000. The TAM is 4,000 x $36,000 = $144 million. Their SAM, limited to companies already subject to SOC 2 requirements, narrows to 2,500 companies or $90 million. Their SOM for the next two years, based on sales capacity, is 200 companies or $7.2 million.