TAM / SAM / SOM calculator
Size your market top-down from the industry and bottom-up from real customers — then see whether they agree. When they don't, that's exactly what investors catch.
Everyone who could ever buy this, per year.
Your product, segment, geography.
$960M SAM
$48M SOM (top-down)
$144M if you won every one
$12M SOM (bottom-up)
$12M
- TAM — total market$8.00B
- SAM — you can serve$960M
- SOM — top-down$48M
- Bottom-up vs top-down SOM4.2× apart
4.2× apart
Worth reconciling before you pitch — usually one percentage or your reachable-customer count is doing too much work.
Benchmark A credible SOM is ~1–10% of SAM in 3–5 yrs; methods within ~2×
Your market, flowing down
TAM → SAM → SOM, each deriving from the last. Your bottom-up SOM of $12M is the number to lead with — the circles show the top-down view it should agree with.
Why it matters
Investors distrust a lonely top-down number — "just 1% of a $50B market" means nothing. They trust a bottom-up SOM built from customers you can actually reach. Reconciling the two before you pitch is the difference between a credible slide and a fast no.
Stop recalculating by hand
Radley Finance keeps this metric — and every other — live from one model, with the same benchmarks built in. Investor-ready in under an hour.
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