Definition
Total Addressable Market is the yearly revenue you would earn if every customer who could buy your product actually did. It is the top of the TAM–SAM–SOM stack: the whole pie, not the slice you can reach this year. Founders use it to size the opportunity before they raise, hire, or pick a wedge.
In the room
How the word shows up in a real conversation.
A founder building GST invoicing software starts with every business that files returns — that is TAM. They then cut to businesses that already buy software (SAM), then to the ones they can sell to in 24 months (SOM). The stack keeps the pitch honest.
Formula
TAM = number of potential buyers × annual revenue per buyer
Common mistake
Pasting a global industry number from a slide and calling it TAM. If you cannot name who pays and what they pay, you do not have a TAM — you have a headline.
India note
India pitches land better when TAM is in rupees and names a buyer (GST-registered SMEs, UPI merchants, tier-2 clinics), not a US SaaS figure copied from another deck.
See also
Serviceable Available Market (SAM)
The share of TAM you can actually reach with your product, channels, and constraints.
Read definition →
Serviceable Obtainable Market (SOM)
The share of SAM you can realistically win in a defined period, given capacity.
Read definition →
Beachhead market
The first narrow customer you can win completely before you expand.
Read definition →
Unit Economics
Financial analysis of the profitability of individual units or transactions.
Read definition →
From the store
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