Know your market before you build a single feature.
Market size determines how big you can grow. Market share determines how realistic your projections are. StartNew calculates TAM, SAM, and SOM for every idea it generates - so you pitch numbers investors actually believe.
TAM, SAM, and SOM - explained simply
Every investor pitch requires these three numbers. Most founders get them wrong because they use top-down estimates that are too large to be credible.
The total global revenue opportunity if you captured 100% of the market. This sets the ceiling and validates that the opportunity is worth pursuing.
The portion of the TAM you can realistically reach given your business model, geography, and target customer profile.
The slice of your SAM you can realistically capture in the next 2-3 years given your resources, go-to-market approach, and competitive position.
Bottom-up sizing beats top-down every time.
A common mistake: "The global fitness market is $100B. If we capture just 1%, that's $1B." Investors hate this. The 1% assumption has no backing - you haven't explained how you get there.
Bottom-up sizing works in reverse: start with your ideal customer profile, estimate how many of them exist, multiply by your planned price point. That gives you a credible, defensible SOM that shows you understand your go-to-market reality.
StartNew builds market sizing using the bottom-up approach - starting from the specific ICP, their paying capacity, and realistic acquisition rates based on comparable companies at early stage.
Market data that flows into your business plan
Most idea tools leave market sizing as homework. StartNew generates it as part of the idea output - and when you convert your idea into a business plan, the market analysis section is pre-populated with:
Setting realistic market share targets
What's a realistic share target for a new entrant? For most early-stage companies, capturing 1-5% of SAM in years 1-3 is credible. For highly focused, well-funded teams, 10% is possible. Claiming 20%+ without a clear distribution advantage is a red flag to investors.
StartNew sets realistic benchmarks based on comparable companies - what did Notion, Figma, or Calendly capture in their first three years in equivalent markets? Your projections are anchored to real precedent, not optimism.
FAQ (common questions)
How does StartNew calculate market size for my idea?
The AI combines industry reports, comparable company benchmarks, and your specific customer profile to estimate market size. It explains the assumptions it uses so you can adjust them for your business plan.
What if my market is very niche or newly emerging?
Emerging markets are often the best ones to enter. StartNew frames the market as "adjacent to X" (a known market) and estimates the emerging segment size based on growth trajectory and early adopter signals.
Can I update the market sizing after generating?
Yes. All sections of your StartNew business plan are fully editable. You can adjust the market size figures, update assumptions, and add your own research - the plan stays your document.
Size your market before you build.
Generate a business idea with full market sizing included - TAM, SAM, SOM, and growth rate.
Analyze Your Market Opportunity - Free