TAM / SAM / SOM Calculator

Size an account-based market using annual contract value, serviceable share, and a realistic obtainable share of SAM.

Use annual values consistently

Start with the number of potential buying accounts, not contacts. Enter annual contract value per account in USD. Serviceable share reflects the portion your product, geography, and delivery model can serve. Obtainable share is a percentage of SAM, not TAM.

Bottom-up market arithmetic

TAM = accounts × annual contract value. SAM = TAM × serviceable percentage. SOM = SAM × obtainable percentage. For 10,000 accounts, $12,000 ACV, 30% serviceable and 5% obtainable: TAM is $120M, SAM $36M, and SOM $1.8M annually.

Assumptions are not market research

Document the source and date behind account counts and pricing. SOM needs a realistic attainment horizon and capacity plan; the output is annual revenue at that share, not cumulative revenue or a forecast. Test multiple scenarios instead of presenting one number as verified market size.

Next steps