Market Sizing TAM SAM SOM Calculator
Calculate your Total Addressable Market (TAM), Serviceable Addressable Market (SAM), and Serviceable Obtainable Market (SOM) with both top-down and bottom-up methodologies for investor-ready market analysis.
Prompt Template
You are a strategy consultant with expertise in market sizing and competitive analysis. Help me calculate my TAM, SAM, and SOM. Business context: - Product/service: [describe what you sell] - Industry: [your industry] - Target customer: [who buys this — be specific about company size, role, geography] - Pricing model: [subscription, one-time, usage-based, etc.] - Average revenue per customer: [annual or monthly] - Current customers: [number, if any] - Geographic focus: [local / national / global — specify countries] - Key competitors: [list 2-5 competitors and their approximate scale] - Year for analysis: [current year or projection year] Please provide: 1. **TAM (Total Addressable Market)** — The total global revenue opportunity if you had 100% market share: - Top-down approach: Start from industry reports, total market value, and narrow down - Bottom-up approach: Total potential customers × average revenue per customer - Show your math clearly with data sources noted 2. **SAM (Serviceable Addressable Market)** — The portion of TAM you can realistically reach given your: - Geographic limitations - Product capabilities vs. full market needs - Customer segment focus - Channel limitations - Calculate as a percentage and dollar value of TAM 3. **SOM (Serviceable Obtainable Market)** — What you can realistically capture in the next 1-3 years: - Based on your current growth rate, team size, and competitive position - Factor in market share of comparable startups at your stage - Provide conservative, moderate, and aggressive scenarios 4. **Market Growth Analysis** — Projected CAGR for your market segment and key growth drivers/headwinds. 5. **Competitive Market Share Map** — Estimate how the current market is divided among key players, and identify the white space you're targeting. 6. **Investor-Ready Summary Slide** — A concise one-slide format with the TAM/SAM/SOM concentric circles and the 3-4 key stats an investor wants to see. 7. **Methodology Notes** — Document assumptions, data sources, and limitations so investors know your analysis is rigorous, not aspirational.
Example Output
# Market Sizing: CloudInvoice — AI-Powered Invoicing for Freelancers
1. TAM (Total Addressable Market)
Top-Down Approach
- Global invoicing & billing software market: $12.3B (2025, Grand View Research)
- SMB segment (< 50 employees): 42% = **$5.17B**
- Freelancer/solo subsegment: ~18% of SMB = **$930M**
Bottom-Up Approach
- Global freelancers (full-time + significant part-time): 78M (Statista 2025)
- % who invoice clients regularly: ~45% = 35.1M
- Willingness to pay for invoicing tools: ~30% = 10.5M potential paying users
- Average annual revenue per user: $96/year ($8/month)
- **Bottom-up TAM: 10.5M × $96 = $1.008B**
TAM Consensus: **~$970M** (average of both approaches)
2. SAM (Serviceable Addressable Market)
| Filter | Reduction | Reasoning |
|--------|-----------|----------|
| English-speaking markets only (US, UK, CA, AU, NZ) | 35% of TAM | Current product is English-only |
| Tech-savvy freelancers (digital, creative, consulting) | 60% of above | Our AI features need digital-first users |
| Not locked into enterprise accounting suites | 80% of above | Excludes QuickBooks/Xero power users |
SAM = $970M × 35% × 60% × 80% = $163M
3. SOM (Serviceable Obtainable Market) — Next 3 Years
| Scenario | Year 1 | Year 2 | Year 3 | Market Share |
|----------|--------|--------|--------|--------------|
| Conservative | $820K | $2.1M | $4.8M | 2.9% of SAM |
| Moderate | $1.2M | $3.8M | $8.5M | 5.2% of SAM |
| Aggressive | $1.8M | $5.5M | $14M | 8.6% of SAM |
**Moderate SOM rationale:** Comparable vertical SaaS tools (Honeybook, Bonsai) captured 4-6% of their SAM within 3 years of product-market fit.
6. Investor-Ready Summary
┌─────────────────────────────────────┐
│ TAM: $970M │
│ Global freelancer invoicing │
│ ┌───────────────────────────┐ │
│ │ SAM: $163M │ │
│ │ English-speaking, digital │ │
│ │ ┌─────────────────┐ │ │
│ │ │ SOM: $8.5M │ │ │
│ │ │ Year 3 moderate │ │ │
│ │ └─────────────────┘ │ │
│ └───────────────────────────┘ │
└─────────────────────────────────────┘
Market CAGR: 14.2% (2025-2030)
78M+ freelancers globally, growing 12% YoY
Incumbents haven't solved AI-native invoicing
7. Methodology Notes
- Industry data: Grand View Research, Statista, Bureau of Labor Statistics
- Freelancer count: Statista Global Freelancer Survey 2025 (conservative estimate — Upwork reports higher)
- ARPU based on competitive pricing analysis of Wave, Bonsai, and Freshbooks free→paid tiers
- **Key assumption:** 30% willingness-to-pay rate. Sensitivity: at 20%, TAM drops to $672M; at 40%, TAM rises to $1.34B
Tips for Best Results
- 💡Investors see inflated TAMs constantly — using both top-down AND bottom-up approaches that converge builds massive credibility.
- 💡Your SOM is what investors care most about — it shows you understand your realistic near-term opportunity, not just the dream.
- 💡Always document your assumptions explicitly. An investor who disagrees with an assumption can adjust the model; one who can't see your assumptions will just discount everything.
- 💡Update your market sizing quarterly — markets shift, and stale numbers in a pitch deck signal you're not paying attention.
Frequently Asked Questions
What is the Market Sizing TAM SAM SOM Calculator prompt?
Calculate your Total Addressable Market (TAM), Serviceable Addressable Market (SAM), and Serviceable Obtainable Market (SOM) with both top-down and bottom-up methodologies for investor-ready market analysis. It's a free ChatGPT prompt template from our Business collection — copy it, fill in the bracketed variables, and paste it into your AI tool.
Which AI tools work with this prompt?
It's written and tested for ChatGPT, Claude and Gemini. Any AI assistant that accepts free-form text prompts will handle it well.
How do I customize this ChatGPT prompt?
Replace the bracketed variables — such as [describe what you sell], [your industry], [annual or monthly] — with your own details before running it. Investors see inflated TAMs constantly — using both top-down AND bottom-up approaches that converge builds massive credibility.
Is this prompt free to use?
Yes. Every prompt on PromptAtlas is free to copy, customize, and use — no signup required.
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