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Market sizing · checked 11 November 2026

Count real customers and multiply by what each pays a year; use top-down figures from reports only as a sanity check.

TAM is the yearly revenue if every possible customer bought, SAM the part your product, price and geography can serve, and SOM the share you can win in the next few years. Antler's worked example counts 1,352 hospitals at $1,000 a licence for a TAM of $1.35 million. If your sum starts at '1% of a billion people', start again.

The steps 18 answers

  1. What are TAM, SAM, and SOM and how do I actually calculate them? Starting Up
  2. How big does my market need to be for this to be a real business? Starting Up
  3. My market is small right now but growing fast. Is that a problem? Starting Up
  4. How do I size a market for India specifically when data is messy? Starting Up
  5. How do I estimate a market size when the product I'm building doesn't have a category yet? Starting Up
  6. Investors keep asking for a top-down TAM slide, but I built my number bottoms-up. Which do I show? Starting Up
  7. My market is huge on paper but almost nobody is actually paying for solutions today. Good sign or bad? Starting Up
  8. How do I size a market I want to sell to businesses outside the big Indian startup hubs? Starting Up
  9. How much of the market do I realistically need to capture for this to be a real business? Starting Up
  10. My total market looks small, but each customer is worth a lot. Can a low-count, high-value market still work? Starting Up
  11. Everyone says my market is too niche to be venture-scale. When are they right, and when are they wrong? Starting Up
  12. How do I research market size and timing when I can only spend a weekend and have no budget for reports? Starting Up
  13. Two of us disagree on how big the opportunity is. How do we resolve a market-size argument between cofounders? Starting Up
  14. How do I size the market and figure out if it's big enough? Starting Up
  15. What are the most common mistakes founders make when sizing their market, and how do I avoid faking a big TAM? Starting Up
  16. How do I research whether a market is big enough to matter but small enough that big players will ignore it? Starting Up
  17. How do I get a real sense of how big my category actually is in India before I bet my capital on it? D2C
  18. How do founders size a market (TAM/SAM) with AI assistance? How Founders Use AI

The readingMost used across these answers

The terms

Total Addressable MarketServiceable Addressable MarketServiceable Obtainable MarketMarket Sizing

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