- SOM (Serviceable Obtainable Market)
- $6,250,000
- SAM (Serviceable Addressable Market)
- $125,000,000
- TAM (Total Addressable Market)
- $500,000,000
- SOM ratio (larger / smaller)
- N/A (fill both to compare)
The diagram uses the top-down chain when present, falling back to bottom-up only when top-down is empty.
Explain my results with AI
Optional. One click generates a short plain-English summary plus improvement suggestions. The calculator and exports still work if this fails.
What a market size calculator is for
A market size calculator turns a messy “how big is this?” question into three nested numbers: the total market (TAM), the slice you can serve (SAM), and the slice you can realistically win (SOM). This page is the same engine as the TAM SAM SOM Calculator. You can fill a top-down chain, a bottom-up chain, or both. The diagram prefers the top-down chain when present and falls back to bottom-up only when top-down is empty. Filling both shows a side-by-side SOM comparison so you can see when the two methods disagree.
Top-down starts from a published or assumed total market in dollars, then multiplies by the percent that is serviceable for your geography or segment, then by the percent you believe you can obtain. Bottom-up starts from people or accounts: how many potential customers, what share you can reach, what win rate you expect, and what each customer is worth per year. Neither method is “the truth.” They are two ways to make the same claim inspectable. A large gap between the two SOM figures is a signal to revisit the weaker assumption, not a bug in the calculator.
How to use top-down and bottom-up
Use top-down when you have an industry report and need a deck-ready funnel from TAM to SOM. Use bottom-up when you can count accounts and prices more honestly than you can defend a global market figure. Use both when a stakeholder will ask why the story does not match the pipeline math. On-screen results are free. Enter an email only if you want to download the report. You do not need an account to run the numbers.
This URL matches the generic “market size calculator” search. The canonical title is TAM SAM SOM Calculator — same formulas, same diagram, same export. If you need keyword-level dollar value instead of a market funnel, use the Keyword Value Calculator. Treat outputs as planning aids. They do not replace diligence on the source of TAM or on win-rate evidence.
Related tools
Explore related free tools in the suite: TAM SAM SOM Calculator, and Keyword Value Calculator. Each report is independent — run the tool that matches the question you need answered today.
Frequently asked questions
Is this different from the TAM SAM SOM Calculator?
No. Same engine and diagram. This page is the generic market-size title; the parent page uses the TAM/SAM/SOM name.
Which method should I trust if they disagree?
Neither automatically. A large SOM ratio means the assumptions disagree. Revisit the weaker-sourced inputs on the chain that is further from your other market data.
Do I need an account?
No. On-screen results are free. Enter an email only if you want to download the report.