GTM Glossary · Market Entry
Total Addressable Market (TAM)
The full annual revenue available if every company that could ever buy your product did so, at your price.
[01]What It Means
TAM is a ceiling, not a plan. It is calculated bottom-up from the number of qualifying accounts multiplied by realistic annual contract value, not top-down from an analyst report about a category. A defensible TAM names its source, its filter, and its date.
[02]Why It Matters
Boards and investors use TAM to judge whether a market deserves headcount. Overstated TAM produces overbuilt teams and disappointed quarters; understated TAM kills expansion cases that would have worked. In Western Europe, TAM per country differs enough that a single European figure is usually meaningless.
[03]Where It Goes Wrong
[04]Related Terms