Market Size Calculator (TAM, SAM, SOM)

Size a market from the bottom up: total, serviceable and obtainable, in dollars or taka, with the customer counts behind each number. Load an example from 15 industries, nine of them where I have worked, to see how it changes.

LinkedIn WhatsApp

Example

Currency Potential customers in total everyone who could ever buy Annual value per customer spend per year in the category Serviceable share (%) reachable with your product, price and channels Obtainable share (%) realistic share of SAM in 3 to 5 years

TAM-total addressable market

SAM-serviceable available market

SOM-

FormulaTAM = customers × annual value · SAM = TAM × serviceable % · SOM = SAM × obtainable %

What to do next

Show the working, step by step

Where I used this

Winning the mass-market entry segment with Galaxy J2 4G and J2 Core reached a run-rate of about 2,600 units a day.

Read the case: Galaxy J2 4G & J2 Core: winning the mass-market entry segment →

Next step, pre-filledTurn it into a budget: Marketing budget planner Then, pre-filledWork back to visitors: Revenue goal funnel Same stageWhere to play: Competitor positioning map

Everything is calculated in your browser. Nothing you type is sent or stored.

Bottom-up beats top-down

"If we get just 1% of a billion-dollar market" is the weakest line in any pitch. Build the number from the customers you can name, the value each brings and the share you can realistically win with your channels and team. Then sanity-check it against competitors' revenue.

Serviceable share narrows TAM to the people your product, price, language and distribution can actually reach today.
Obtainable share should reflect your sales capacity and the competition, not ambition.

Get new free tools by email. One short note when a new tool or essay goes live. No spam, unsubscribe any time.

Need a market size investors will trust?

Bring your assumptions to a free 30-minute call, and I will help you build a bottom-up number you can defend.

Book a free call

Questions

What is the difference between TAM, SAM and SOM?

TAM is everyone who could buy. SAM is the part you can serve with your current product and channels. SOM is the share of SAM you can realistically win in the next few years.

Should I use top-down or bottom-up sizing?

Bottom-up, built from customer counts and value per customer, is more credible. Use top-down industry reports only as a cross-check.

What obtainable share is realistic?

It depends on competition and resources. Single-digit percentages of SAM over three to five years are common planning assumptions for new entrants.

Market size (TAM, SAM, SOM) calculator