# TAM SAM SOM calculator: size your market bottom-up A TAM SAM SOM calculator sizes a market in three layers from two numbers you can defend: how many customers could buy, and what each pays a year. TAM is every possible customer times the price, SAM is the share you can serve today, and SOM is the share of those you can realistically win. Use it free, with no signup, at https://getlaunchlist.com/tools/tam-calculator. Updated 2026-10-15. ## What you enter - **Every customer who could buy this**: Companies or people with the problem, anywhere, counted from a public source. - **What one customer pays a year**: Your planned price. For a monthly plan, multiply by 12. - **Share you can serve (SAM)**: The customers your product, language, countries and sales channel actually fit today, as a percentage. - **Share of those you can win (SOM)**: Customers you can realistically win in your planning window, usually three years, as a percentage. - **Annual revenue you are aiming for**: Your revenue goal, used to work out how many customers it needs. - **Top-down market size from a report**: Optional. A figure from a report you can name and link, to compare with your own count. ## How it's calculated The calculator sizes your market bottom-up: it counts customers and multiplies by what each pays. It has no table of industry sizes built in, because a market size you cannot trace back to a source is not a number you can defend. Every figure comes from your inputs. - **TAM (total addressable market) = every customer who could buy × annual price.** - **SAM (serviceable addressable market) = TAM customers × share you can serve × annual price.** - **SOM (serviceable obtainable market) = SAM customers × share you can win × annual price.** - **Customers your goal needs = revenue goal ÷ annual price**, rounded up, and that as a share of SAM customers. - **Your TAM vs the report = bottom-up TAM ÷ the top-down figure you enter.** It assumes one price for every customer and one purchase a year. If you sell several plans, use the average you expect to collect per customer. ## Choosing your numbers Count customers from a source you can name. For businesses in the US, the Census Bureau's Statistics of U.S. Businesses tabulates firms by industry and employment size, so you can count, for example, agencies with 10 to 49 staff. For consumers, start from a count of the people with the problem, not the whole population. The share you can serve narrows that to the countries, languages and channels you can actually sell through today. The share you can win is best built from the bottom: the leads you can reach each month, times the share you close, over three years. The default inputs describe a made-up product with 200,000 possible customers at $600 a year. They show how the calculator works and are not typical values for anything. ## How to read the result TAM shows the ceiling, SAM the market you can sell to now, and SOM the revenue you can plan around. The useful check is the goal line: if your revenue goal needs a bigger share of SAM than you expect to win, the plan rests on a higher price, a wider market or a better close rate. If you enter a top-down figure and your own TAM comes out far larger, one of your inputs is too generous. ## What moves it Price and customer count multiply, so each moves every line by the same factor. The two shares only move SAM and SOM. Of all the inputs, the share you can win is the least certain, which is why a [pre-launch waitlist](https://getlaunchlist.com/glossary/pre-launch-waitlist) is a cheap way to test it: the share of the people you reach who sign up is a first, real reading of interest. ## Sources - [U.S. Census Bureau, 2022 Statistics of U.S. Businesses](https://www.census.gov/data/tables/2022/econ/susb/2022-susb-annual.html): Where to count US businesses by industry and size for the customer count. No figure from it is built into the tool. Checked 2026-10-15. ## Frequently asked questions ### What are TAM, SAM and SOM? TAM, the total addressable market, is the revenue if every possible customer bought your product. SAM, the serviceable addressable market, is the part your product, countries and sales channels can actually serve. SOM, the serviceable obtainable market, is the part of SAM you can realistically win in your planning window, usually a few years. ### How do you calculate TAM SAM SOM? Bottom-up: count the customers who could buy and multiply by what each pays a year to get TAM. Multiply the customer count by the share you can serve to get SAM, and by the share of those you can win to get SOM, each times the same price. ### What is the difference between top-down and bottom-up market sizing? Top-down starts from a published industry figure and takes a percentage of it. Bottom-up counts the customers you could sell to and multiplies by your price. Bottom-up is easier to defend because every number in it can be checked, and a top-down figure is still useful as a cross-check on whether your own count is too generous. ### Where do I find the number of potential customers? For businesses, use a public count by industry and size, such as the US Census Bureau Statistics of U.S. Businesses, a national business register, or a directory you can filter. For consumers, start from the people who have the problem rather than everyone in a country. Write down the source next to the number. ### Can SOM be larger than my revenue goal needs? Yes, and that is the comfortable case: the goal needs a smaller share of your serviceable market than you expect to win. If the goal needs more than your expected share, the plan depends on a higher price, a wider market or winning more of the customers you reach. ### How can a waitlist help with market sizing? The share you can win is the least certain number in the calculation. A waitlist measures it directly: share a page with the customers you can reach and count how many sign up. That is a real reading of interest you can put next to the estimate. ## Related tools - [Startup idea validator](https://getlaunchlist.com/tools/idea-validation-scorecard.md): Score the evidence behind your startup idea and choose your next validation step. - [Pre-launch MRR calculator](https://getlaunchlist.com/tools/prelaunch-mrr-projector.md): Project launch-day MRR and the first year of revenue from your waitlist, price and churn. - [Startup runway calculator](https://getlaunchlist.com/tools/startup-runway-calculator.md): Work out how many months of cash you have from your burn rate, revenue and growth.