Total addressable market (TAM)

Total addressable market (TAM) is the total revenue opportunity available for a product or service if it captured 100% of its potential market — the ceiling on demand before accounting for competition, distribution reach, or any one company's actual ability to capture it.

It's commonly estimated top-down, starting from industry research figures and narrowing to the relevant segment, or bottom-up, multiplying the number of potential customers by expected revenue per customer. TAM is often broken down further into SAM (serviceable available market — the part reachable given a company's business model and geography) and SOM (serviceable obtainable market — what it could realistically capture against competitors). No single "correct" TAM exists for most markets; estimates vary widely with the source data and assumptions used, so a TAM figure should always be read alongside its methodology.

TAM is used in strategic planning, fundraising, and prioritizing which markets to pursue; a large TAM signals room to grow but says nothing about how much of it a specific company can actually win, which is closer to what market share and competitive intelligence address. A common pitfall is inflating TAM by defining the market too broadly or applying unrealistic capture-rate assumptions, so figures used for investment decisions deserve scrutiny of the method, not just the headline number.