Bottom-up calculator
TAM SAM SOM calculator
Example inputs · replace with your sourced figures
The one hard input: use a census, registry, or directory export. Where this number comes from →
- TAM
- $35,046,000
- SAM
- $14,018,400
- SOM
- $700,920
per year
We size the market bottom-up at $35,046,000 TAM — 29,500 countable customers at $1,188 a year. Applying a 40% serviceable filter gives a $14,018,400 SAM, and a 5% obtainable share gives a $700,920 SOM over three years. The customer count and price need sources; the two percentages are labelled assumptions.
The count and price should have sources. The 40% serviceable filter and 5% obtainable share are assumptions—not evidence.
The math, visible without JavaScript
| Output | Formula |
|---|---|
| TAM | Countable target customers × annual price |
| SAM | TAM × serviceable filter |
| SOM | SAM × obtainable share |
What this calculator will not let you do
Most calculators accept an industry-size number and a hopeful percentage. This one does not. An industry’s revenue is often customers paying someone else for a different product; “1% of a $5B industry” is not a smaller version of your market.
Start with something countable: a trade-association census, licence registry, or directory export. Your price is yours. The serviceable filter and obtainable share are assumptions, and the copied sentence says so.
A worked bottom-up example
The Coin Laundry Association counts about 29,500 US laundromats. At an illustrative $99 per month, that is roughly $35M TAM. A 40% serviceable filter gives about $14M SAM; a 5% obtainable share gives about $700K ARR.
The $5B US laundromat industry figure measures customers paying laundromats, not laundromats paying for management software. Those are different units. The smaller number is the defensible one.
FAQ
Is this TAM SAM SOM calculator free?
Yes. It runs in your browser, requires no sign-up, and does not store what you enter.
How do you calculate TAM, SAM and SOM?
Start with countable target customers times annual price for TAM. Apply the share you can serve today for SAM, then the share you can honestly win in one to three years for SOM.
Why is there no top-down option?
Industry revenue often measures a different payer and product. This calculator deliberately requires a count of buyers and your price instead.
What is a realistic SOM percentage?
For an early plan, single digits of SAM are usually easier to defend. Above 25%, name the incumbent whose customers you expect to win.