TAM calculator: market size and how many leads your outbound list holds
A TAM calculator sizes your total addressable market bottom-up: the number of accounts that fit your customer profile, times what each is worth a year. For outbound, the same count times contacts per account times the share you can reach gives your list size; divide by new contacts a month for the months of runway left.
The figures loaded are an example, not a benchmark. Replace each with your own; leave the optional fields empty to skip them.
Runs in your browser. Measure reachable from a sample: find and verify emails for 100 contacts, and use the share that passed.
Market size
- TAM (accounts)
- 4,000
- SAM (accounts)
- 4,000
Outbound list
- Contacts in SAM
- 12,000
- Reachable list size
- 7,200
- New contacts a month
- 2,167
- List runway
- 3.3 months
4,000 accounts × 3 contacts × 60% reachable = 7,200 people you can email. At 2,167 new contacts a month (100/day × 5 days × 52 ÷ 12 weeks), that list lasts about 3.3 months.
Next step
Your reachable list is 7,200 people. Every bounce spends one of them and your domain's reputation with it.
A finite market can't absorb wasted sends. Verify each batch before it goes into a sequence, so the contacts you start are ones the email can reach.
- Drop your list as a CSV
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Ready to verify now? Verify the list
Sample result
3,600 reachable contacts at 2,167 new a month gives you about 1.7 months of outreach.
- Reachable contacts
- 3,600
- TAM (per year)
- $48,000,000
- SAM (accounts)
- 2,000
What this means for you
A small market runs out fast, so make every address count by verifying before you send.
- TAM, SAM and SOM in accounts and revenue
- Contacts per account and reachable share
- Months to work the list at your pace
- Optional fields skipped when left empty
- TAM
- SAM/SOM
- List size
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
How do I calculate my TAM and outbound list size?
- Enter how many companies fit your ideal customer profile, from your own filter in a data tool or a public business count.
- Set the serviceable share (regions, sizes and industries you can sell to now) and, optionally, revenue per account and the share you expect to win.
- Enter how many people per account you would email and the share with a findable, valid address, measured on a sample of your own.
- Enter new contacts per sending day and sending days per week to see the reachable list size and how many months it lasts.
Example
- You enter
- 4,000 accounts at $12,000 a year, 50% serviceable, 5% expected win share, 3 contacts per account, 60% reachable, 100 new contacts a day, 5 days a week.
- You get
- TAM $48,000,000 a year, SAM 2,000 accounts ($24,000,000), SOM 100 accounts ($1,200,000), and 3,600 reachable contacts that last about 1.7 months at 2,167 a month.
- Limits
- No limit; optional fields are skipped when empty. Runs in your browser.
How do I calculate TAM?
Bottom-up, TAM is the number of potential customer accounts times the annual revenue one account is worth: 4,000 accounts × $12,000 a year = $48 million. The account count is the part to get right, and it should come from a filter you can reproduce: the companies in your target industries, sizes and regions in your CRM or data tool, or a public count such as the US Census Bureau's County Business Patterns (establishments by industry and county) and Statistics of U.S. Businesses (firms by size). Eurostat's structural business statistics and the UK's Companies House search serve the same purpose in Europe and the UK.
Top-down figures from analyst reports describe a whole industry, not the accounts you can sell to, which is why the calculator only takes numbers you supply.
How do I calculate TAM, SAM and SOM?
SAM, the serviceable available market, is the part of TAM you can serve today: TAM × the share of accounts in regions, sizes and segments your product and team cover. SOM, the serviceable obtainable market, is the share of SAM you expect to win in a given period: SAM × your expected share. With 4,000 accounts, 50% serviceable and 5% obtainable, SAM is 2,000 accounts and SOM is 100.
Each share should be an assumption you can defend: serviceable from your coverage, obtainable from your own win rate and sales capacity. Leave obtainable empty if you have no basis for it yet.
How many leads do I need for cold email?
As many as your send volume uses up before you can re-contact anyone: new contacts per day × sending days per week × 52 ÷ 12 is how many people a month a sequence consumes. At 100 a day, 5 days a week, that's about 2,167 a month. Compare it with the reachable list (SAM accounts × contacts per account × reachable share) and you know how long the market lasts at that pace.
If the runway is short, the fix is in the inputs: widen the profile (more accounts), add personas (more contacts per account), or slow down. The cold email volume calculator works out the inboxes that volume needs.
What does reachable share mean, and how do I measure it?
It is the share of the contacts you want whose email address you can find and that passes verification. There is no standard figure: it varies by industry, role and data source, which is why it's an input. Measure it on a sample: pick 100 contacts from your target list, find their addresses, verify them, and use the share that came back valid.
The share matters twice. It sets how many people you can reach at all,, and the addresses that fail would otherwise bounce, which raises your bounce rate on every send.
Can I do this in Excel or Google Sheets?
| Figure | Spreadsheet formula (A accounts, V value per account, S serviceable and R reachable as decimals, C contacts per account, D per day, W days a week) |
|---|---|
| TAM | =A*V |
| SAM accounts | =A*S |
| Reachable list | =A*S*C*R |
| New contacts a month | =D*W*52/12 |
| Runway in months | =A*S*C*R/(D*W*52/12) |
The calculator runs the same formulas and keeps the market and the list numbers side by side.
Who uses this tool, and for what?
- Founders
- Turn a pitch-deck TAM into an account count you can reproduce, and see SAM and SOM from your own coverage and win rate.
- Cold emailers
- Check how many months a niche lasts at your daily volume before you buy more inboxes or widen the profile.
- Agencies
- Show a client how big their reachable list really is before promising meetings from it.
- Sales leaders
- Size territories by accounts and contacts, and see which segment runs out first at current pace.
What can’t this tool tell you?
- It has no market data. The account count, revenue per account and every share are yours, so the result is only as good as they are.
- Revenue per account is an average; a market with a few large accounts and many small ones is better sized segment by segment.
- Runway assumes each contact is started once. Re-contacting after months, or adding new companies as they appear, extends it.
- Reachable share comes from your own sample. A small sample gives a rough figure.
Common questions
- How do you calculate TAM?
- Bottom-up: the number of accounts that fit your customer profile times the annual revenue per account. Top-down estimates from industry reports are a cross-check, not a substitute.
- How do you calculate TAM, SAM and SOM for a startup?
- TAM = all fitting accounts × revenue per account. SAM = TAM × the share you can serve now. SOM = SAM × the share you expect to win. Use your own coverage and win rate for the two shares.
- What is a TAM calculation example?
- 4,000 target companies × $12,000 a year = $48 million TAM. If you serve half of them, SAM is $24 million; winning 5% of SAM gives a SOM of $1.2 million.
- How do I calculate TAM bottom up?
- Count the accounts that match your profile from a reproducible filter (CRM, data tool or public business counts), then multiply by the annual value of one account. The calculator does that and carries the count into your outbound list size.
- What is the difference between total addressable market and total available market?
- They are usually used as the same thing: everyone who could buy the product. Serviceable available market (SAM) is the narrower part you can serve today.
- How do you find total addressable market size?
- Filter for companies matching your industry, size and region in your data tool or a public source such as the US Census Bureau's business counts, then multiply by annual revenue per account.
Sources
The calculator makes the case better than we can.
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