Waterfall enrichment cost calculator: what each found email really costs
In short: Enter your contacts and each provider in waterfall order with its cost, find rate and whether it charges per lookup or per find. See what each step adds, its cost per extra email, coverage so far, and the cost per sendable email once verification failures are removed. Limit: Every input is your number. The calculator doesn't know any provider's price, coverage or accuracy.
A waterfall tries one email finder, then sends the contacts it missed to the next, and so on. Each step only sees the leftovers, so later steps find fewer emails and, if they charge per lookup, cost far more per email they add. Enter your providers in order with your own costs and find rates to see the cost per found email, per sendable email, and which step is the expensive one.
Price: this tool is free. Checking a whole email list is from $9/mo, and the first 100 checks are free with Google, no card. See pricing
Your plan price ÷ the credits it includes.
The providers loaded are an example. Enter yours in the order the waterfall runs them, with the cost from your own plan and the share each one finds on the contacts that reach it.
Leave blank if you don't verify the found emails.
From your last verification run on found emails.
- Emails found
- 692 (69.2%)
- Total cost
- 1,385 credits
- Cost per found email
- 2 credits
- Cost per sendable email
- 2 credits
692 of 1,000 contacts get an email, 308 are left without one. Enrichment costs 1,385 credits, and 692 emails are left to send to.
| Step | Tried | Found | Cost | Per email it added | Coverage so far |
|---|---|---|---|---|---|
| Provider 1 | 1,000 | 450 | 450 credits | 1 credit | 45% |
| Provider 2 | 550 | 165 | 165 credits | 1 credit | 61.5% |
| Provider 3 | 385 | 77 | 770 credits | 10 credits | 69.2% |
Provider 3 costs 10 credits for each email it adds, more than twice what the first step pays. Without it, this step's 770 credits is saved and its 77 emails are lost, unless a later step finds them. Paying it per find instead of per lookup also lowers the figure.
Next step
Found is not the same as deliverable.
A waterfall returns an address for each contact it can, from guesses, databases and pattern matches. A mailbox check on the found emails before they go into a sequence shows which ones exist, and gives you the real fail rate for this calculator.
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Sample result
3 providers find 692 emails for 1,000 contacts; step 3 costs 10 credits for each email it adds.
- Cost per found email
- 2.00 credits
- Emails found
- 692 (69.2%)
- Total cost
- 1,385 credits
What this means for you
Late per-lookup steps pay for the hardest leftovers; check each step's cost per email it adds.
- Each step on the leftovers
- Per-find or per-lookup
- Cost per email each step adds
- Cost per sendable email
- Waterfall
- Enrichment
- Credits
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
Also in: Português (Brasil) · Español
How do I calculate the cost of a waterfall enrichment?
- Enter how many contacts go into the waterfall, and whether your costs are in credits or dollars. With credits, add the price of one credit to see dollars as well.
- Add each provider in the order the waterfall runs them, with its cost and the share of contacts reaching that step it finds an email for. The providers loaded are an example; replace them.
- Set each provider's charge rule: only when it finds an email, or for every contact it tries.
- Optionally, add the cost of verifying each found email and the share that fail, to get the cost per email you can actually send to.
Example
- You enter
- 1,000 contacts and three providers in order: 1 credit per find at 45%, 1 credit per find at 30% of what's left, and 2 credits per lookup at 20% of the rest.
- You get
- 692 emails found (69.2%): 450, then 165 of the 550 left, then 77 of the 385 left. 1,385 credits in total, 2.00 credits per found email; the third step spends 770 credits for 77 emails, 10 credits each against 1 for the first.
- Limits
- Up to 8 providers; every price and find rate is your own input; runs in your browser.
How is the waterfall cost worked out?
Step by step on what is left. With 1,000 contacts and a first provider finding 45%, 450 emails are found and 550 contacts go to step two. If step two finds 30% of those, it adds 165, and 385 go to step three. A step charged per find costs its price × the emails it found; a step charged per lookup costs its price × every contact it tried, found or not.
Cost per found email is total enrichment cost ÷ emails found. The more telling number is each step's cost per email it added: a provider charging 2 credits per lookup that finds 20% of 385 leftovers spends 770 credits for 77 emails, 10 credits each, against 1 credit each for the first step. Clay, for one, describes waterfall enrichment as a way to "search sequentially across multiple tools until you find a valid match" (Clay); this calculator works for that or any other tool that runs finders in sequence.
What find rate should I enter for later steps?
The rate on the contacts that reach that step, not the provider's rate on a fresh list. Later steps get the hard leftovers: people at small companies, new job changers, unusual name formats. Their find rate on leftovers is usually lower than the rate the same provider gets as the first step, so taking a vendor's headline coverage figure overstates what step three adds.
The way to get the number is your own run history: in the enrichment table, count the rows where each provider returned the email, divided by the rows that reached it. Re-check it per list, because coverage depends heavily on the market and seniority of the contacts.
Why count verification in the cost?
Because a found email is a candidate, not a confirmed mailbox. Finders return addresses from databases, pattern guesses and catch-all domains, and the cheapest way to lose a sending domain is to send to the ones that don't exist. Verifying every found email before it goes into a sequence adds a small cost per email and removes the failures; the cost per sendable email is total spend ÷ the emails that pass.
That figure is the one to compare against other sources. A waterfall that finds 80% at a lower cost per found email can still lose to a smaller list if a larger share of its emails fail. Verify once, at the end of the waterfall, on the final address for each contact; checking earlier pays for addresses a later step replaces.
Can I calculate it in a spreadsheet?
Yes. With contacts in B1, and for each step its cost in column B, find rate in C (as a decimal) and contacts reaching it in D, starting at row 3:
| Figure | Formula |
|---|---|
| Contacts reaching step 1 | =B1 in D3 |
| Emails found by the step | =D3*C3 in E3 |
| Contacts reaching the next step | =D3-E3 in D4 |
| Step cost, charged per find | =E3*B3 |
| Step cost, charged per lookup | =D3*B3 |
| Cost per email the step added | =step_cost/E3 |
| Cost per sendable email | =(total_cost+found*verify_cost)/(found*(1-fail_rate)) |
Who uses this tool, and for what?
- GTM engineers
- Decide whether a fourth provider in a Clay table earns its credits or just adds cost on the hardest leftovers.
- Cold emailers
- Compare the cost per sendable email of a waterfall against buying a list that's already been verified.
- Agencies
- Price enrichment into a client quote per sendable contact, not per row going in.
- RevOps
- Set a budget for enriching a target account list before running it.
What can’t this tool tell you?
- Every input is your number. The calculator doesn't know any provider's price, coverage or accuracy.
- It treats each step's find rate as fixed for the contacts that reach it. In a real run the rate varies by company size, country and seniority.
- Emails a provider returns wrongly (an address for someone else) count as found. Only verification and replies show those.
- Phone numbers and other enrichment fields aren't counted; it covers the email step only.
Common questions
- What is waterfall enrichment?
- Running several email or data providers in sequence: the first is tried on every contact, and only the contacts it misses go to the next. It raises coverage over any single provider, at the cost of paying several of them.
- Is a waterfall cheaper than one provider?
- Per contact covered, often not; per email found, it depends on the order and the charge rules. Put the providers that charge only on a find, or that find the most per credit, first, and check each later step's cost per email it adds.
- Does the order of providers matter?
- Yes. Each step only sees the contacts the earlier ones missed, so a provider charged per lookup costs least when it comes after the others have taken the easy contacts. Rerun the calculator with your providers in a different order, adjusting each find rate to what it gets at that position.
- Where do I get the find rates?
- From your own enrichment history: rows where a provider returned an email, divided by the rows that reached it. Vendor coverage claims are measured on their chosen lists, not on your leftovers.
- Does this know Clay's credit prices?
- No, and no other tool's either. Prices and credit costs change with plans, so enter the cost from your own plan. With credits, add the price of one credit to see dollar figures.
- What fail rate should I use for verification?
- The share of found emails your last verification run marked invalid or unknown. If you haven't verified found emails before, run a sample first; the result is your number.
Sources
The calculator makes the case better than we can.
Every per-address model above recurs each time you clean. A monthly plan with no per-email fees does not.
- Pro is never cut off: the first 100,000 emails a month run at full speed, then big lists run slower
- The email finder and enrichment included
- Published limits, so nothing is a surprise later
Plans from $9 a month, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.