Enter your market assumptions
Use the filters below to size the market from a broad population down to serviceable and obtainable revenue.
Example data table
This sample illustrates how a top-down approach narrows a broad market into practical revenue opportunities.
| Input or output | Sample value | Meaning |
|---|---|---|
| Total market entities | 1,000,000 | Entire market population before filters. |
| Target segment share | 25% | Buyers matching your profile. |
| Serviceable geography | 60% | Coverage across supported regions. |
| Channel reach | 45% | Share you can access through campaigns. |
| Expected penetration | 12% | Likely share you can win. |
| Effective revenue per customer | $1,320.00 | Annual revenue plus uplift. |
| TAM value | $330,000,000.00 | Segment revenue before reach constraints. |
| SAM value | $89,100,000.00 | Reachable revenue after filters. |
| SOM value | $10,692,000.00 | Realistic revenue capture estimate. |
Formula used
Base revenue per customer = Annual revenue per customer, or average order value × purchase frequency.
Effective revenue per customer = Base revenue per customer × (1 + uplift %).
TAM entities = Total market entities × target segment %.
SAM entities = TAM entities × serviceable geography % × channel reach %.
SOM entities = SAM entities × expected penetration %.
TAM value = TAM entities × effective revenue per customer.
SAM value = SAM entities × effective revenue per customer.
SOM value = SOM entities × effective revenue per customer.
Projected year value = Current value × (1 + annual growth %)^(year - 1).
Net present value = Sum of projected values ÷ (1 + discount rate)^year.
How to use this calculator
- Enter a label for the market unit you want to count.
- Add the broad market size before applying any filters.
- Estimate what share fits your ideal target segment.
- Enter geography coverage and channel reach assumptions.
- Select a pricing model and fill the related revenue inputs.
- Include uplift, growth, discount, and scenario range values.
- Press Calculate TAM to show the result above the form.
- Use the CSV or PDF buttons to export your summary.
Frequently asked questions
1. What does top-down TAM mean?
It estimates market size by starting with a broad population, then applying filters such as segment fit, geography, reach, and pricing.
2. Why does this calculator also show SAM and SOM?
TAM is useful, but SAM and SOM make planning practical. They show what you can serve and what you may actually win.
3. Should I use annual revenue or order value?
Use annual revenue for subscriptions or repeat contracts. Use order value and frequency when buyer spending comes from multiple yearly purchases.
4. What is the uplift percentage for?
Uplift captures additional revenue from upsells, bundles, premium tiers, expansion seats, or add-on services beyond the base purchase.
5. Why include a discount rate in a TAM model?
A discount rate converts future market values into present terms. This helps when comparing long-range opportunities or investment cases.
6. How should I choose the penetration rate?
Use a realistic share based on competition, budget, conversion rates, sales capacity, and time-to-market. Conservative estimates are usually safer.
7. What does the scenario band change?
It creates low and high TAM cases around the base estimate. This helps explain uncertainty during planning or investor discussions.
8. Is top-down TAM enough by itself?
No. It works best when paired with bottom-up evidence such as pipeline data, win rates, territory coverage, and actual customer spending.