TAM SAM SOM Calculator

1

Enter Market Parameters

Input your total target population (number of potential customers or businesses) and the average annual spend per customer. These two inputs define the ceiling of your market opportunity.

2

Set Serviceable Percentages

Enter the percentage of TAM you can realistically serve (SAM%) based on geography, language, and product-market fit. Then enter the percentage of SAM you can capture (SOM%) — typically 1–10% for early-stage companies.

3

Review TAM, SAM, and SOM

The calculator instantly shows your Total Addressable Market, Serviceable Addressable Market, and Serviceable Obtainable Market, plus 2× and 5× scaling scenarios to illustrate your growth path.

4

Explore Projections and Investor Summary

Switch to the 5-Year Projection tab to see how your market evolves over time. Use the Competitive Positioning tab to generate an investor-ready narrative that anchors your pitch in credible market data.

Total Addressable Market (TAM)

TAM = Total Target Population × Average Annual Spend

Total Target Population is the global or national count of potential customers. Average Annual Spend is how much each customer spends in your category per year. TAM represents 100% market capture — a theoretical ceiling, not a realistic target.

Serviceable Addressable Market (SAM)

SAM = TAM × (Serviceable %) / 100

Serviceable % is the fraction of TAM you can realistically reach given your geography, product fit, language, and distribution channel. For a US-only SaaS product targeting English-speaking SMBs, your SAM% might be 15–25% of a global TAM.

Serviceable Obtainable Market (SOM)

SOM = SAM × (Capture %) / 100

Capture % is the realistic market share you can win from competitors in the near term. Early-stage startups typically target 1–5% of SAM. SOM is the number you defend in an investor pitch — it should tie directly to your sales capacity and GTM strategy.

Projected Market at Year N

Projected Market = Base Market × (1 + Growth Rate)^N

Growth Rate is the annual market expansion rate (industry CAGR). N is the number of years. This compound growth formula shows how TAM, SAM, and SOM evolve over your planning horizon — relevant for Series A and beyond fundraising narratives.

TAM (Total Addressable Market) The total global or national revenue opportunity for a product or service category, assuming 100% market capture. TAM is a theoretical ceiling — it frames the scale of the opportunity but does not represent a realistic near-term target.

SAM (Serviceable Addressable Market) The portion of TAM that a business can realistically serve given its product, geography, language, and go-to-market capabilities. SAM narrows TAM to the realistic competitive arena.

SOM (Serviceable Obtainable Market) The portion of SAM a company can capture in the near term, based on sales capacity, competitive dynamics, and pricing. SOM is the most defensible number in a market sizing exercise — investors scrutinize it most closely.

Top-Down Market Sizing A market sizing approach that starts with total industry size from third-party reports (e.g., IDC, Gartner) and applies a series of percentages to narrow down to SAM and SOM. Fast but dependent on the quality of the external data source.

Bottom-Up Market Sizing A market sizing approach that starts from unit economics — price per customer × number of reachable customers — and aggregates up to a market estimate. More credible in investor pitches because it ties directly to observable sales data.

CAGR (Compound Annual Growth Rate) The mean annual growth rate of a market over a specified period, assuming the growth compounds year-over-year. Used to project TAM, SAM, and SOM into the future. Industry CAGR estimates are available from market research firms.

Market Capture Rate The percentage of a target market (SAM) that a company wins as revenue. Early-stage companies typically achieve 1–5% capture. Capture rate is constrained by sales capacity, brand awareness, and competitive intensity.

ACV (Annual Contract Value) The average annualized revenue from a single customer contract. Used in bottom-up market sizing: SAM = (Number of addressable accounts) × ACV. Particularly relevant for B2B SaaS companies with subscription pricing models.

Market sizing is the foundation of every credible business plan and investor pitch. TAM, SAM, and SOM give you three concentric lenses on your opportunity: the total ceiling, the realistic playing field, and the winnable prize.

TAM, SAM, and SOM: The Three Market Lenses

Market sizing is the foundation of every credible business plan and investor pitch. TAM, SAM, and SOM give you three concentric lenses on your opportunity: the total ceiling, the realistic playing field, and the winnable prize. A common mistake is leading with TAM ('the global market is $500B') without grounding the pitch in a defensible SOM. Investors know that a 1% share of a $500B market sounds easy but rarely is — they want to see how you get to your SOM number, not just what it is. Use this calculator to stress-test your assumptions across best-case (5× capture), base-case (current), and conservative (0.5×) scenarios before walking into any funding conversation.

Top-Down vs. Bottom-Up Market Sizing

Top-down sizing starts with published industry reports (Gartner, IBISWorld, Statista) and works down by applying filters for geography, customer segment, and product fit. Bottom-up sizing starts from unit economics: estimated customers x average contract value x reachable percentage. Top-down is faster for early pitches; bottom-up is more credible for investor due diligence. The most persuasive market sizing uses both methods and shows they produce convergent estimates.

Using Market Size to Set Strategy

Market size shapes strategic decisions beyond fundraising. A TAM under $1B typically cannot support venture-scale returns. SAM determines sales territory strategy and go-to-market structure. SOM translates directly to revenue targets: a realistic SOM of $10M in year three implies specific sales headcount, marketing spend, and customer success capacity. Updating these numbers annually as actual sales data accumulates is more valuable than the initial estimate.

What is the difference between TAM, SAM, and SOM?+

TAM (Total Addressable Market) is the total revenue opportunity if you captured 100% of the market. SAM (Serviceable Addressable Market) is the portion you can realistically serve given your geography, product fit, and business model. SOM (Serviceable Obtainable Market) is the share of SAM you can actually capture in the near term — typically 1–10% for early-stage companies.

How do you calculate total addressable market (TAM)?+

Top-down: TAM = Total Target Population × Average Annual Spend per Customer. Bottom-up: TAM = (Number of reachable accounts) × Average Contract Value, then scaled to the full market. Both approaches should be cross-validated — sophisticated investors expect you to show your math and cite credible sources for population and spend figures.

What is the difference between top-down and bottom-up market sizing?+

Top-down starts with total industry size from analyst reports and applies percentages to narrow to SAM and SOM. It is quick but depends on report quality. Bottom-up starts from unit economics — price per customer and number of reachable customers — and builds up. Bottom-up is more credible in investor pitches because it ties directly to observable sales data and your actual go-to-market capacity.

How do investors evaluate market size?+

For venture-scale businesses, investors typically want a TAM of at least $1B. But more importantly, they scrutinize whether SAM and SOM assumptions are realistic. A well-defended $50M SOM with a clear path to 2–5× growth is more compelling than an inflated $10B TAM with no credible capture route. Lead with your SOM, defend it with bottoms-up logic, and show the TAM to frame the ceiling.

What is a realistic SOM capture rate?+

Early-stage startups typically target 1–5% of SAM as their initial SOM. Established SMBs in defensible niches might realistically capture 5–15% of a well-defined SAM. Capture rates above 20% are credible only in highly specialized or regulated markets with limited competition. Conservative estimates are always better — investors will adjust upward if your logic is sound, but they will discount an overly optimistic SOM.

🌎 Market Parameters

📺 Market Capture

📈 Growth Assumptions

📊 Market Size Summary

TAM / SAM / SOM Breakdown

📄 Investor-Ready Summary

How to Use This Calculator

Enter Market Parameters

Set Serviceable Percentages

Review TAM, SAM, and SOM

Explore Projections and Investor Summary

Formula & Methodology

Key Terms Explained

Real-World Examples

Market Sizing: TAM, SAM, and SOM Explained

TAM, SAM, and SOM: The Three Market Lenses

Top-Down vs. Bottom-Up Market Sizing

Using Market Size to Set Strategy

Frequently Asked Questions

🌎 Market Parameters

📺 Market Capture

📈 Growth Assumptions

📊 Market Size Summary

TAM / SAM / SOM Breakdown

📄 Investor-Ready Summary

How to Use This Calculator

Enter Market Parameters

Set Serviceable Percentages

Review TAM, SAM, and SOM

Explore Projections and Investor Summary

Formula & Methodology

Key Terms Explained

Real-World Examples

Market Sizing: TAM, SAM, and SOM Explained

TAM, SAM, and SOM: The Three Market Lenses

Top-Down vs. Bottom-Up Market Sizing

Using Market Size to Set Strategy

Frequently Asked Questions

Keep Exploring

Related calculators

Guides & articles

Related Calculators