Calculator Tools
TAM SAM SOM Calculator
Calculate TAM, SAM, and SOM in your browser. Top-down and bottom-up methods, customer counts, share ratios, and a multi-year revenue projection.
Method
Quick scenarios
Top-down inputs
Start from a published industry total and apply two share percentages.
The annual revenue if you served every possible customer worldwide. Use the largest credible industry figure.
Filter for geography, segment, language, regulation, channel, or product fit. Range: 0 to 100.
Realistic capture in years one to three given competitors, sales capacity, and channel reach. Range: 0 to 100.
Used to imply customer counts at every layer. Multiply monthly ARPU by 12.
Year-over-year growth rate of the SOM. Compounded annually in the projection.
Year-by-year revenue and cumulative table. Capped at 20 years.
Results
$10,000,000,000
~16.7M customers at this ARPU
$1,200,000,000
~2M customers in this slice
$60,000,000
~100K customers to win
1 in 8 of TAM revenue falls inside the SAM.
1 in 20 of SAM revenue you plan to capture as SOM.
Market layers, drawn to scale
Widths are proportional to the layer revenue against the TAM. A 6 percent minimum keeps tiny SOMs visible.
SOM / TAM: 0.6%
Total Addressable Market
Serviceable Available Market - 12% of TAM
Serviceable Obtainable Market - 5% of SAM
Revenue projection
SOM compounded annually at 25%. Year one starts at the SOM.
5 years - 25% YoY
| Year | Revenue | Cumulative |
|---|---|---|
| 1 | $60,000,000 | $60,000,000 |
| 2 | $75,000,000 | $135,000,000 |
| 3 | $93,750,000 | $228,750,000 |
| 4 | $117,187,500 | $345,937,500 |
| 5 | $146,484,375 | $492,421,875 |
Plain-text summary
Paste into a pitch deck speaker note, a board update, a fundraise memo, or a Slack thread.
TAM SAM SOM Calculator summary Method: Top-down (start from TAM) Currency: USD Market layers TAM (Total Addressable Market): $10,000,000,000 SAM (Serviceable Available Market): $1,200,000,000 (12% of TAM) SOM (Serviceable Obtainable Market): $60,000,000 (5% of SAM, 0.6% of TAM) Implied customer counts at ARPU $600 / year TAM customers: 16,666,667 SAM customers: 2,000,000 SOM customers: 100,000 Revenue projection (5-year, 25% YoY) Year 1: $60,000,000 (cumulative $60,000,000) Year 2: $75,000,000 (cumulative $135,000,000) Year 3: $93,750,000 (cumulative $228,750,000) Year 4: $117,187,500 (cumulative $345,937,500) Year 5: $146,484,375 (cumulative $492,421,875)
How each layer is calculated
- TAM (Total Addressable Market)
- Top-down: published industry TAM; Bottom-up: potential customers x annual ARPU
- The total annual revenue you could capture if you served every possible customer worldwide with no constraints.
- SAM (Serviceable Available Market)
- TAM x SAM share %
- The slice of TAM you can actually serve given your geography, segment, language, regulation, channel, or product fit.
- SOM (Serviceable Obtainable Market)
- SAM x SOM share %
- The realistic share of SAM you expect to win in years one to three given the competitors, your channel reach, and your sales capacity.
- SOM as a share of TAM
- SOM / TAM (also: SAM% x SOM% / 100)
- A sanity check on the whole funnel. If this number is above one or two percent for a young company, investors usually push back.
- Implied customers per layer
- Layer revenue / Annual ARPU
- Translates each market layer into a count of buying customers so the numbers are easier to defend.
- Revenue projection
- Year N revenue = SOM x (1 + growth)^(N-1)
- Treats the SOM as year-one captured revenue and compounds it at the chosen annual growth rate.
Notes and caveats
- Top-down vs bottom-up: investors trust bottom-up because every input (customer count, ARPU) is something a founder can defend. Use top-down to anchor against an analyst report, not as the only method.
- SOM is not market share forever: SOM is the realistic capture in the next one to three years given your sales capacity and channels, not the eventual market share at maturity.
- ARPU is annual: the implied customer counts and projection use revenue per customer per year. Multiply monthly ARPU by 12 before entering it.
- Growth is compounded annually: the projection compounds the SOM at the entered growth rate. Real businesses grow unevenly; treat the line as a best-case glide path, not a forecast.
- Currency is display only: the selector formats numbers with Intl.NumberFormat. No exchange rates are fetched and no conversion is applied.
- Local only: nothing you type is uploaded. Every calculation runs in your browser.
How to use
- Pick a method: Top-down to start from a published industry TAM, or Bottom-up to start from a count of potential customers and an annual revenue per customer.
- Pick a currency for display formatting (no FX conversion is applied) and load a Quick scenario to see realistic shape numbers before typing your own.
- Enter your inputs. The result panel updates on every keystroke; SAM and SOM share percentages must be between 0 and 100 and the projection horizon is capped at 20 years.
- Read the three result cards (TAM, SAM, SOM) with the share ratio and implied customer counts under each, then check the proportional bar visualisation underneath.
- Review the year-by-year revenue projection with cumulative totals, then use Copy summary to grab a plain-text report for a pitch deck speaker note, a board update, a fundraise memo, or a Slack thread.
About this tool
TAM SAM SOM Calculator builds the canonical three-layer market sizing chart investors expect to see on the third slide of a pitch deck: Total Addressable Market (TAM), Serviceable Available Market (SAM), and Serviceable Obtainable Market (SOM). Pick the method that fits the data you have. Top-down starts from a published industry total and applies a SAM share to filter for geography, segment, language, regulation, channel, or product fit, then a SOM share to land on the realistic capture in the first one to three years. Bottom-up starts from a count of potential customers worldwide and multiplies by an annual revenue per customer to derive the TAM, then applies the same SAM and SOM share percentages; bottom-up is what investors trust because every input (customer count, ARPU) is something the founder can defend. Both methods produce the three layer numbers, the ratio of each layer to the one above it, the SOM as a share of TAM (the sanity-check ratio that flags an unrealistic story when it climbs above one or two percent for a young company), and the implied customer counts at every layer when an annual revenue per customer is supplied. A multi-year revenue projection treats the SOM as year-one captured revenue and compounds it at the chosen annual growth rate (capped at twenty years) so a fundraise narrative can show both the day-one market and the trajectory. Four quick scenarios are built in for each method, covering a seed-stage SaaS, a global marketplace, a vertical SaaS, a regional consumer app, an SMB SaaS, a developer tool, an enterprise niche, and a creator tool, so a first-time founder can see realistic shape numbers before changing them. A visualisation draws the three layers as proportional bars (with a six percent floor so a tiny SOM is still visible) and the projection table shows year-by-year and cumulative revenue. Currency formatting covers USD, EUR, GBP, CAD, AUD, JPY, INR, and TRY through Intl.NumberFormat and is display only with no FX conversion. Useful for founders building a seed or Series A deck, product managers writing a market opportunity memo, MBA students working through a market sizing case, marketers validating a campaign budget, agencies pricing a new vertical, and anyone refining the third slide before a pitch meeting. Everything runs locally in your browser; the numbers you type are never uploaded.
Free to use. Works in your browser. No signup, no login.
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