Financial Glossary
Market Sizing Analysis
Market sizing analysis estimates the total addressable market (TAM), serviceable addressable market (SAM), and serviceable obtainable market (SOM) for a product or business. TAM is the total revenue opportunity if 100% of potential buyers purchased. SAM narrows to the segment the business can realistically serve given its go-to-market model, geography, and product scope. SOM is the realistic near-term market share. Two primary approaches exist: top-down (starting from industry data and applying penetration rates) and bottom-up (building from unit economics -- price times addressable customer count). Investors and management teams use market sizing to evaluate growth potential and prioritize capital allocation.
Problem & Application
Bottom-up example for a campground reservation software provider: there are approximately 16,000 private campgrounds in the US (industry estimate). Average software spend per park is $3,000 per year. TAM = $48,000,000. Of those, roughly 40% (6,400 parks) actively use reservation software and might switch platforms, making SAM = $19,200,000. A new entrant realistically capturing 5% of SAM in year three produces a SOM of $960,000 ARR. Top-down approach: the US outdoor hospitality industry generates an estimated $10B+ in annual revenue; software and services represent roughly 0.5% of operator revenue, yielding a similar TAM range. Credible market sizing uses both methods and reconciles them. For SaaS founders pitching investors and for fractional CFOs supporting board presentations, defensible market size modeling -- not back-of-envelope guesses -- is the baseline expectation.
In Short
Market sizing analysis helps businesses assess potential opportunities and make data-driven decisions for market entry or expansion.