Market Sizing TAM SAM SOM Calculator
Calculate Total Addressable Market (TAM), Serviceable Available Market (SAM), and Serviceable Obtainable Market (SOM)
Worked Examples
Example 1: B2B SaaS Market Sizing
Problem: Project management SaaS for mid-market. Total businesses: 30M. Target: 100-1000 employees (5% of businesses). Realistic reach: 10% of segment. $1,200 ARPU. Calculate TAM/SAM/SOM and Year 1-5 revenue at 1/5/10% SOM share.
Solution: Market Sizing:\n- Total population: 30M businesses\n- Target segment: 5% = 1.5M businesses (100-1K employees)\n- Realistic reach: 10% of 1.5M = 150K businesses\n- Avg revenue per user: $1,200\n\nTAM = 30M × $1,200 = $36B\nSAM = 1.5M × $1,200 = $1.8B (5% of TAM)\nSOM = 150K × $1,200 = $180M (10% of SAM)\n\nRevenue Projections:\n- Year 1 (1% of SOM): $1.8M\n - Customers: 1,500\n - Assumes: 10 AEs, 150 deals/year each\n- Year 3 (5% of SOM): $9M\n - Customers: 7,500\n - Assumes: 40 AEs\n- Year 5 (10% of SOM): $18M\n - Customers: 15,000\n - Assumes: 75 AEs\n\nValidation:\n- 10 AEs × 150 deals = 1,500 customers ✓\n- Market share: 1% of SOM, 0.05% of SAM, 0.001% of TAM ✓\n- Realistic and defensible\n\nInvestor Pitch:\n'$36B TAM, targeting $1.8B SAM (mid-market PMOs). Realistic capture: $180
Result: TAM: $36B | SAM: $1.8B | SOM: $180M | Year 5: $18M revenue (10% SOM, 1% SAM)
Example 2: Consumer Mobile App Market
Problem: Fitness app for US adults. Total US adults: 260M. Health-conscious segment: 30%. Smartphone users: 85%. $60/year subscription. Project Year 1-3 at 0.1%/0.5%/1% SOM.
Solution: Population Math:\n- Total adults: 260M\n- Health-conscious: 30% = 78M\n- Smartphone: 85% of 78M = 66.3M\n- Avg revenue: $60/year\n\nTAM = 260M × $60 = $15.6B (all US adults)\nSAM = 78M × $60 = $4.68B (health-conscious)\nSOM = 66.3M × $60 = $3.98B (health + smartphone)\n\nRevenue Projections:\n- Year 1 (0.1% SOM): $3.98M\n - Users: 66,300 (0.025% of US adults)\n - Acquisition: Paid social, influencers, ASO\n- Year 2 (0.5% SOM): $19.9M\n - Users: 331,500 (0.13% of US adults)\n - Growth: Viral referrals + paid scaling\n- Year 3 (1% SOM): $39.8M\n - Users: 663,000 (0.25% of US adults)\n - Competitive: Peloton, Nike Training Club\n\nRealism Check:\n- 66K users Year 1 requires ~180 signups/day\n- At $20 CAC × 66K = $1.3M acquisition cost\n- With $60 ARPU, LTV/CAC ratio needs optimization\n
Result: TAM: $15.6B | SAM: $4.7B | SOM: $4B | Year 3: $40M (1% SOM) | VC-scale market
Example 3: Niche B2B Market Validation
Problem: Compliance software for biotech companies. 5,000 biotech companies globally, 50% need compliance software, realistic reach 30%. $25K ARPU. Is this venture-scale?
Solution: Market Sizing:\n- Total population: 5,000 biotech companies\n- Target segment: 50% need compliance = 2,500 companies\n- Realistic reach: 30% of 2,500 = 750 companies\n- Avg revenue: $25,000/year\n\nTAM = 5,000 × $25K = $125M\nSAM = 2,500 × $25K = $62.5M\nSOM = 750 × $25K = $18.75M\n\nRevenue Projections (conservative):\n- Year 1 (5% SOM): $937K\n - Customers: 37 (10% of reachable 750)\n - Realistic for enterprise sales\n- Year 3 (15% SOM): $2.8M\n - Customers: 112\n- Year 5 (30% SOM): $5.6M\n - Customers: 225 (30% of 750)\n\nAnalysis:\n- TAM $125M is too small for VC (typically need $1B+)\n- Max realistic revenue ~$15-20M (capturing 80% SOM)\n- Market is niche and constrained\n\nOptions:\n1. Bootstrap (SOM supports $5-10M ARR company)\n2. Expand TAM: add pharma, medical devices\n - N
Result: TAM $125M too small for VC | Expand to pharma/medtech or bootstrap | $5-10M ARR potential
Frequently Asked Questions
What is TAM, SAM, and SOM?
TAM (Total Addressable Market) is total demand if you had 100% market share globally. SAM (Serviceable Available Market) is the segment you can realistically target with your product and business model. SOM (Serviceable Obtainable Market) is the portion you can realistically capture short-term given competition and resources. Example: TAM $100B, SAM $10B (your segment), SOM $500M (realistic capture).
How do I calculate TAM?
Top-down: total population × average revenue per user. Bottom-up: number of potential customers × average sale price. Value-theory: estimate value you create and how much customers would pay. Use multiple approaches to validate. Be realistic—overstating TAM damages credibility with investors.
What's a realistic SOM for a startup?
Year 1: 0.1-1% of SAM. Year 3: 1-5% of SAM. Year 5: 3-10% of SAM. These are general guidelines. Network-effect businesses may grow faster; complex sales cycles slower. Validate against go-to-market capacity—can your team actually reach and convert this many customers?
Why do investors care about TAM?
Investors seek large markets. A $10B+ TAM can support a billion-dollar company capturing 10%. A $100M TAM caps potential exit size. VCs need TAM >$1B for venture scale. But TAM alone doesn't matter—must demonstrate path to capture meaningful share (SAM/SOM).
How granular should my market segmentation be?
SAM should be specific: not 'all businesses' but 'B2B SaaS companies with 50-500 employees in North America.' Too broad lacks credibility; too narrow limits opportunity. Balance: narrow enough to be defensible target, broad enough for venture scale. Be able to name companies in your SAM.
What if my TAM seems too small?
Options: (1) Expand product to adjacent markets, (2) Redefine TAM more broadly (but credibly), (3) Accept smaller TAM and bootstrap rather than raise VC, (4) Focus on high ARPU to make smaller customer base venture-scale. A $100M TAM with $50K ARPU (2,000 potential customers) can support a $30M company.