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TAM SAM SOM Calculator
Size your market the way investors expect to see it. Work top-down from a total market figure, or bottom-up from customers and pricing, to get your total addressable market (TAM), serviceable market (SAM), and obtainable market (SOM) — the heart of your pitch deck's market slide.
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→ Your market size
Credible, conservative SOM
Your SOM is 1.0% of TAM. Investors reward a single-digit, bottom-up SOM far more than a big slice of a headline number.
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Save the current inputs as a scenario, then compare best, base, and worst side by side. Saved in this browser.
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<iframe src="https://planypals.com/embed/tam-sam-som-calculator" title="TAM SAM SOM Calculator" width="100%" height="760" loading="lazy" style="border:1px solid #ddd3bf;max-width:760px"></iframe> <p style="font:13px/1.5 sans-serif">Free <a href="https://planypals.com/tools/tam-sam-som-calculator">TAM SAM SOM Calculator by Planypals</a></p>
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Market sizing is an estimate built on your assumptions. Use credible, sourced figures — investors check the inputs, not just the total.
How TAM, SAM, and SOM are calculated
Market sizing answers one investor question: how big can this get? The three figures nest inside one another — TAM is the whole category, SAM is the part you can serve, and SOM is the part you can realistically win soon. There are two ways to get there.
- Top-down: SAM = TAM × serviceable %; SOM = SAM × obtainable %
- Bottom-up: TAM = potential customers × average annual revenue; then narrow by reach % and share %
A worked example
Suppose your category is worth $5B a year (TAM). If your product and geography can serve 20% of it, your SAM is $1B. If you can realistically capture 5% of that serviceable market in a few years, your SOM is $50M in annual revenue. The bottom-up method reaches a similar place from the other direction — say 2,000,000 potential customers paying $1,200 a year — and a matching pair of estimates is far more convincing than either alone.
Top-down vs. bottom-up market sizing
Top-down starts from a big industry number and narrows it with percentages — fast, but easy to inflate and easy for investors to dismiss (“why 20%?”). Bottom-up builds from your own units: how many potential customers exist, and what each pays. It is harder to fake because every input is defensible, which is why investors trust it more. The strongest market slide shows a bottom-up SOM cross-checked against a top-down TAM — the two arriving at a similar place is the proof.
What is a realistic SOM?
Be conservative. A SOM of a few percent of your serviceable market over three to five years is credible for most startups; claiming double-digit share quickly reads as naïve unless you have the traction to back it. SOM isn't a ceiling on ambition — it is evidence you understand that winning a market takes time, capital, and execution. A modest, well-reasoned SOM builds more confidence than a huge one you can't defend.
How a market slide loses credibility
- Top-down only. A percentage of a giant number impresses no one — pair it with a bottom-up build.
- Confusing TAM with SOM. The market is not your revenue; SOM is the realistic near-term slice.
- Unsourced numbers. Cite the industry reports and assumptions behind each figure — investors check the inputs.
- A SOM that's too big. An aggressive share claim undermines the credibility of the whole deck.
The market slide rarely stands alone. Investors read it next to your traction and your model, so it pays to understand how to value a startup and exactly what slides to include in a pitch deck before you build the rest.
→ Beyond the calculator
Put your market size in a deck that raises
A TAM, SAM, and SOM are three numbers — the market slide is a story. We turn your sizing into a sourced, visual slide inside a full investor pitch deck: narrative, design, and the financials that make the opportunity believable.
Frequently asked questions
- They are three nested measures of market size. TAM (total addressable market) is the total annual revenue if every possible buyer used your category. SAM (serviceable addressable market) is the slice your business model and geography can actually serve. SOM (serviceable obtainable market) is the realistic portion of that you can capture in the near term. Each is a subset of the one above it.
- Two ways. Top-down starts from a total market figure and narrows it: SAM = TAM × your serviceable share, SOM = SAM × your obtainable share. Bottom-up builds up from your own numbers: TAM = total potential customers × average annual revenue per customer, then narrow by the share you can reach and win. Bottom-up is harder to dispute because every input is yours — this calculator does both.
- Investors trust bottom-up more because it's built from customer counts and pricing you can defend, rather than a percentage of a giant headline number. The strongest market slides show a bottom-up SOM cross-checked against a top-down TAM. Use the toggle in the calculator to run both and compare.
- Be conservative. A SOM of a few percent of your serviceable market over three to five years is credible for most startups; claiming double-digit share quickly is a red flag unless you have the traction to prove it. The point of SOM is to show you understand it's a realistic near-term target, not the whole market.
- Yes. It runs in your browser, nothing is stored, and there's no sign-up. You can opt in to receive the results as a PDF for your deck. When you want the market sizing built into a full investor pitch deck with sourced research, that's what our pitch deck design service does.