TAM SAM SOM Calculator
Size your market in minutes. Enter your numbers, pick a method, and get TAM, SAM, and SOM with investor benchmarks built in.
Calculate Market SizeStart from total industry size and narrow down by segment and capture rate. Best when you have an industry report figure.
Total industry revenue in dollars. Find this in industry reports (Statista, IBISWorld, CB Insights).
What % of the total market can you realistically reach? Consider geography, product fit, and distribution.
What % of your SAM can you win in the next 1-3 years? Solo founders typically start at 1-5%.
What is TAM, SAM, and SOM?
TAM, SAM, and SOM are three market sizing metrics used by founders, investors, and product teams to understand market opportunity. They form a funnel from total theoretical ceiling down to near-term realistic target. Learn more on Wikipedia's TAM article.
Total Addressable Market
The total revenue opportunity if your product captured 100% of the market. It ignores geography, competitors, and operational limits. TAM sets the ceiling.
TAM = Total Customers x Average Revenue Per CustomerExample: Every professional developer in the world who could benefit from a code review tool.
Serviceable Addressable Market
The portion of TAM you can actually reach given your product scope, geography, and distribution. SAM is who you can sell to, not who you could theoretically sell to.
SAM = TAM x Serviceable Segment %Example: Professional developers in the US and Europe using CI/CD pipelines who pay for developer tools.
Serviceable Obtainable Market
The realistic slice of SAM you can win in the next 1-3 years given your current resources, team size, and competitive position. SOM is your actual target.
SOM = SAM x Realistic Capture Rate %Example: Solo founder targeting 2% of SAM in year 1-2, growing to 5% by year 3.
Top-Down vs Bottom-Up: Which Method to Use?
Both methods should give roughly the same answer. If they diverge significantly, your assumptions need revisiting. Use both as a sanity check.
| Top-Down | Bottom-Up | |
|---|---|---|
| Starting point | Industry report or analyst figure | Individual customer count x price |
| Investor reception | Common but often questioned | More credible, shows customer understanding |
| Best used when | You have a reliable third-party market figure | You can identify and count your actual customers |
| Risk | Easy to inflate. Market reports include tangential segments | Can undercount if you narrow ICP too aggressively |
| Solo dev friendly | Yes, quick to estimate from SaaS reports | Yes, LinkedIn / App Store counts work well |
TAM SAM SOM Example: Solo Developer Productivity SaaS
A solo founder building a productivity tool for indie developers, subscription SaaS at $15/month. Here is how the market sizing looks using the bottom-up method.
Professional developers globally who buy software tools: ~5,000,000. At $180/year ARPU, TAM = $900M.
US + Europe solo devs and indie founders who actively pay for productivity tools: ~12% of total. SAM = $108M.
Year 1-3 target at 2% capture of SAM via indie hacker communities, Product Hunt, and SEO. SOM = $2.16M.
Common TAM SAM SOM Mistakes Founders Make
Inflated market sizing is one of the top reasons investors lose confidence in early-stage pitches. These are the patterns they have seen hundreds of times.
A "$50B cloud infrastructure market" is not your TAM if you are building a niche developer CLI tool. TAM must reflect actual potential customers for your specific product, not the adjacent category it lives in.
Saying "if we just capture 1% of the $50B market, we make $500M" is a red flag. It skips SAM entirely. Investors call this the "1% fallacy." Show you understand who your actual buyers are.
If your SOM capture rate is 50–100% of SAM, your assumptions are not credible. Even well-funded companies rarely exceed 20–30% market share in a competitive segment. For early-stage solo founders, 1–5% is realistic.
If your top-down TAM says $5B but your bottom-up says $200M, the bottom-up is almost certainly closer to reality. Market reports often include tangential segments that do not buy your product.
What Investors Expect from TAM SAM SOM
Benchmarks vary by funding stage and investor type. Use these as a guide, not a rigid rule. A credible argument matters more than hitting a threshold. Y Combinator's guide on TAM for investors is worth reading.
| VC / Seed | Angel / Pre-seed | Bootstrapped | |
|---|---|---|---|
| TAM | $1B+ | $100M-$999M | $10M-$99M |
| VC funds need potential for large exits. Angels and bootstrappers can build profitable businesses in smaller markets. | |||
| SAM | $100M+ | $10M-$99M | $1M-$9M |
| SAM determines growth ceiling for your go-to-market motion. Too small and you cannot grow beyond early traction. | |||
| SOM (Year 3) | $10M+ | $1M-$9M | $100K-$999K |
| SOM is what you are actually targeting. It should connect directly to your revenue projections in the financial model. | |||
Related Free Tools
Frequently Asked Questions
Frequently asked.
TAM (Total Addressable Market) is the total revenue opportunity if you captured 100% of your market. SAM (Serviceable Addressable Market) is the portion of TAM you can actually reach with your product and distribution. SOM (Serviceable Obtainable Market) is the slice of SAM you can realistically capture in the near term, usually 1-3 years.
Top-down starts from a total industry figure (e.g., "$30B developer tools market") and applies percentage filters to arrive at SAM and SOM. Bottom-up starts from the number of real target customers and multiplies by average revenue per user. Bottom-up is more credible to investors because it is grounded in customer-level assumptions rather than analyst reports.
Most institutional VCs want to see a TAM of at least $1 billion, because they need the possibility of a large exit to justify their fund model. For angel investors or bootstrapped founders, a TAM of $100M-$500M is still a strong opportunity, especially if you can capture a meaningful share of a well-defined SAM.
A credible SOM for a pre-revenue or early-stage startup is typically 1-5% of SAM. If your SOM is above 10% of SAM, investors will likely push back unless you have strong evidence for rapid adoption. For solo founders in year one, a SOM of $500K-$2M is a realistic and fundable target for bootstrapped products.
Yes. This calculator is designed with SaaS and solo developer products in mind. The bottom-up method works especially well for SaaS. Enter your total potential customer count and your annual plan price (ARPU), then filter to your realistic segment and capture rate.
For top-down sizing, industry reports from Statista, IBISWorld, or CB Insights are common sources. For bottom-up, use LinkedIn for professional counts, App Store categories for app markets, or NAICS codes to find US business counts by industry. Always cite your source when presenting to investors.
TAM shows the ceiling. It tells investors the opportunity is large enough. But SOM is what you are actually going after in the next 12-24 months. A credible SOM with a clear go-to-market plan demonstrates that you understand your market, not just its theoretical size. A TAM slide without a convincing SOM is a red flag.
SAM is the total market you can serve given your product scope and geography, it is who could realistically buy from you. SOM is what you will actually win in the near term given your current resources, competitive position, and sales capacity. SOM is always a subset of SAM.
Knowing your metrics
is the easy part.
Shipping is the hard part.
FoundStep is the project management tool that won't let indie devs procrastinate. Validate your idea in 7 questions. Lock your scope. Ship, or kill it.