Market Size Calculator
Work out your TAM, SAM and SOM, then get a blunt critique of the assumptions behind them and what to do to validate them.
Nothing yet
Fill in the form above and your results will appear here.
What the three numbers mean
TAM is everyone who could conceivably buy: the whole population you entered, times what each would pay in a year. It is the least useful of the three, and the one most often quoted.
SAM is the share you could actually serve, given where you operate and who you can reach. This is where most estimates go wrong, usually by being far too generous.
SOM is what you could realistically win in three years. If your SOM is larger than the revenue of the biggest company already doing this, one of your assumptions is wrong.
The number that is usually wrong
It is almost always the reachable share. Founders enter the percentage of people who have the problem rather than the percentage they can actually get in front of with the budget and channels they have. Those are different numbers, often by an order of magnitude.
Revenue per customer is the second most common error, usually because it is set at the price a founder hopes to charge rather than what a comparable product charges today.
How to make this real
The arithmetic here is exact and free — it is done in your browser, not estimated. What is worth your time is the critique underneath it. Take the three validation steps it gives you and actually do one this week. A market size you have tested against five real conversations is worth more than a spreadsheet with more decimal places.