Define the customer
Specify buyer type, geography, company size, use case, and purchasing ability.
TAM SAM SOM Calculator
Turn your audience and pricing assumptions into transparent total, serviceable, and realistically obtainable market estimates.
Clear market-sizing assumptions
Estimate market size
Use annual revenue per customer and realistic serviceability percentages.
Understand TAM, SAM, and SOM
TAM represents the full annual revenue opportunity if every relevant customer bought the product. SAM narrows that universe to customers the current product and business model can serve. SOM estimates the realistic share the company could capture within a defined time horizon.
Market sizing is only as credible as its assumptions. Document the source and date for customer counts, explain pricing, account for geographic and product limitations, and compare the top-down result with a bottom-up sales-capacity model.
Simple market sizing formulas
TAM = customers × annual revenue; SAM = TAM × serviceable %; SOM = SAM × obtainable %Build a defensible market estimate
A useful market model helps prioritize a launch segment and makes every assumption easy to challenge.
Support the inputs
Use current public data, customer research, and realistic annual pricing.
Model obtainable share
Connect SOM to channels, sales capacity, conversion, retention, and time.
Market sizing FAQ
What is the difference between TAM and SAM?
TAM is the entire theoretical market, while SAM is the subset your current product, geography, and operating model can serve.
How should a startup estimate SOM?
Use achievable acquisition capacity, expected conversion, competition, retention, and a defined period rather than selecting an arbitrary market-share percentage.
Should market size use revenue or customers?
Both are useful. Customer count shows scale, while annual revenue translates that scale through a clear pricing assumption.