Free TAM SAM SOM Calculator
TAM SAM SOM Calculator
Size your market like a pro. Top-down or bottom-up — get investor-ready numbers with visual output for your pitch deck.
Start with total market and filter down to your slice.
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Calculate TAM, SAM, and SOM for your pitch deck using top-down or bottom-up methodology. Enter your market data and assumptions to generate investor-ready market sizing with the classic concentric circles visualization. Bottom-up approach earns the "investor-ready" badge — VCs prefer data-driven sizing over broad estimates.
How to Size Your Market
- 1
Choose your approach
Top-down starts with total market size and narrows by geography, segment, and capture rate. Bottom-up starts with your unit economics and scales up. VCs generally prefer bottom-up — it's more grounded.
- 2
Enter market data
Top-down: total market size or (total customers × average revenue). Bottom-up: reachable customers, average revenue, total serviceable customers, total market customers.
- 3
Apply filters and capture rates
Geographic focus, customer segment fit, product applicability, and realistic year 1/3/5 capture rates. Be honest — VCs will pressure-test these numbers.
- 4
Use the output in your pitch deck
Copy the TAM/SAM/SOM numbers and the concentric circles visualization directly into your investor presentation. The methodology note shows VCs you did the work.
Why Market Sizing Matters
Every pitch deck needs slide 3
Market size is typically the third slide in a pitch deck, right after the problem and solution. Investors need to see that the opportunity is big enough to justify venture-scale returns. This tool builds that slide for you.
Bottom-up builds credibility
Saying "it's a $50B market" is hand-waving. Saying "there are 200K businesses like ours, we can reach 5K in year 1 at $2K/year, so our SOM is $10M" — that's credible. Bottom-up shows you understand your unit economics.
TAM ≠ your market
First-time founders confuse TAM with opportunity. TAM is the total pie. SAM is the slice you could serve. SOM is what you'll realistically capture. Investors care most about SOM trajectory — show them year 1/3/5 growth.
Sanity-check your business plan
If your SOM requires 40% market share in year 1, something is wrong. Market sizing forces you to pressure-test your growth assumptions against reality before investors do it for you.
Frequently Asked Questions
What is the difference between TAM, SAM, and SOM?
TAM (Total Addressable Market) is the total revenue opportunity if you had 100% market share globally. SAM (Serviceable Addressable Market) is the portion you can actually serve given your geography, product, and customer segment. SOM (Serviceable Obtainable Market) is what you'll realistically capture in the near term given competition and resources.
Should I use top-down or bottom-up market sizing?
Use both and triangulate. Top-down is faster and good for sanity-checking. Bottom-up is more credible with investors because it's grounded in your unit economics. If the two approaches differ by more than 3x, revisit your assumptions — one of them is wrong.
What is a good SOM for a startup?
For year 1, 1-5% of SAM is typical. By year 5, 5-15% is ambitious but achievable. If your model shows 30%+ market share in year 3, investors will be skeptical. The key is showing a credible path from SOM to SAM over time.
Do VCs actually care about TAM?
Yes, but not the way founders think. VCs use TAM as a filter — if the total market is under $1B, it's probably too small for venture returns. But they evaluate your company on SOM trajectory and unit economics. A $100B TAM means nothing if your SOM path is unclear.
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