Leads to buy calculator: how many leads for N valid contacts?
In short: Enter the number of valid contacts you want, the share of a list you expect to verify as valid, the share already in your CRM and any other share you will drop. The calculator gives the number of leads to buy, the checks you will run and the cost per valid contact. Limit: Every rate is your estimate; a wrong valid rate gives a wrong quantity.
Divide the valid contacts you want by the share of a bought list that survives: the leads not already in your CRM, the leads you keep after your own filters, and the share that verifies as valid. Type those three shares and the calculator returns the leads to buy, rounded up, with a table for a lower valid rate.
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. Check your list free nowSee pricing
The numbers below are examples. Replace them with your own target, the valid rate you expect and the prices you are quoted.
From a past list from the same source, if you have one.
Wrong title, role addresses, excluded countries.
- Leads to buy
- 2,924
- Share that ends up usable
- 68.4%
- Checked
- 2,500
- Invalid removed
- 500
- Total cost
- $158.70
- Cost per valid contact
- $0.08
Buy 2,924 leads, drop 424 before checking, check the other 2,500 and keep 2,000 valid, new contacts.
80
- Leads to buy
- 2,924
- Total cost
- $158.70
75
- Leads to buy
- 3,119
- Total cost
- $169.28
70
- Leads to buy
- 3,342
- Total cost
- $181.39
65
- Leads to buy
- 3,599
- Total cost
- $195.34
60
- Leads to buy
- 3,899
- Total cost
- $211.62
| Valid rate (%) | Leads to buy | Total cost |
|---|---|---|
| 80 | 2,924 | $158.70 |
| 75 | 3,119 | $169.28 |
| 70 | 3,342 | $181.39 |
| 65 | 3,599 | $195.34 |
| 60 | 3,899 | $211.62 |
Formula: leads to buy = valid contacts wanted divided by ((1 - duplicate share) x (1 - other drops) x valid rate), rounded up. Every rate is your input, not a measured figure.
Sample result
With the example rates, 2,924 leads give 2,000 valid, new contacts.
- Leads to buy
- 2,924
- Checked
- 2,500
- Cost per valid contact
- $0.0794
What this means for you
That is after dropping duplicates and other leads, then removing invalid addresses; every rate is one you type.
- Your own valid rate
- Duplicates dropped first
- Cost per valid contact
- Table for a lower rate
- Leads
- Valid rate
- Calculator
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
Find your real valid rate before you buy the next list.
- Take a sample of the list you already hold, or the sample a vendor sends, and keep its addresses in one column.
- Upload or paste it at /verify. Every address gets a live mailbox check, and the first 100 email checks are free with a Google sign-in, no card.
How do I work out how many leads to buy?
- Type how many valid, new contacts you want from the purchase.
- Type the share you expect to verify as valid; use the rate from the last list you bought from the same source if you have one.
- Type the share already in your CRM and the share you will drop for other reasons, such as wrong titles.
- Add the prices you were quoted if you want the cost, then read the number of leads to buy and the table for a lower valid rate.
- Buy that many, verify the list and keep the valid addresses.
Example
- You enter
- Example: 2,000 valid contacts wanted, 80% valid, 10% already in your CRM, 5% dropped for other reasons, $50 per 1,000 leads and $5 per 1,000 checks.
- You get
- Buy 2,924 leads. 424 are dropped before checking, 2,500 are checked, 500 are invalid and 2,000 valid, new contacts remain. Total cost $158.70, $0.0794 per valid contact. At a 60% valid rate the same plan needs 3,899 leads.
- Limits
- Runs in your browser; nothing is uploaded. Every number is typed by you; the values here are examples.
How is the number of leads worked out?
Every list loses addresses at three points: the ones you already have, the ones your own filters drop, and the ones that fail verification. The calculator multiplies the three surviving shares together to get the share of a purchase that becomes a usable contact, then divides your target by it and rounds up. Checks are counted only on the leads left after the first two drops, because those are the ones you would verify.
Where does the valid rate come from?
From you; the calculator has no built-in rate. The most reliable number is the result of verifying a sample or an earlier list from the same source: the share marked valid. The table shows the same purchase if the rate comes in 5, 10, 15 and 20 points lower, so you can see what a worse list would cost. A source that cannot show a sample is a reason to test it before buying a large list; the purchased email list checker is one way.
What does the cost per valid contact include?
The price of the leads you buy plus the price of checking the leads that are not duplicates, divided by the valid contacts you wanted. Both prices are optional and are the ones you type. To compare several offers on this number, use the lead list vendor comparison calculator.
Who uses this tool, and for what?
- Cold emailers
- Size a list purchase so the campaign still starts with the number of valid contacts you planned.
- Agencies
- Put a buy quantity and a cost per valid contact in a client quote.
- Sales ops
- Set a purchase request that accounts for duplicates and a failing share.
What can’t this tool tell you?
- Every rate is your estimate; a wrong valid rate gives a wrong quantity.
- It assumes the same rates apply to the whole purchase, which is simpler than real lists.
- It does not judge the quality or fit of a list, only how many addresses survive.
- The valid rate of a purchase is only known after it has been verified.
Common questions
- What valid rate should I type?
- The share of a similar list from the same source that came back valid. If you have none, test a sample first.
- Why does the answer round up?
- You cannot buy part of a lead, and rounding down would leave you short of your target.
- Should duplicates come out before or after verification?
- Before. There is no reason to pay to check addresses you already hold, so the calculator counts checks only on the new leads.
- Does the calculator know any vendor's prices?
- No. The prices are blank-able fields with example values; type the ones you were quoted.
- Does a higher valid rate mean a better list?
- It means fewer wasted sends. Titles, companies and fit still matter and are outside this tool.
- Is anything uploaded?
- No. The numbers stay in your browser.
A tidy list can still be full of dead addresses.
Extracting, deduplicating and syntax checks all work on the text of an address. None of them can tell whether the mailbox exists. Only the server that hosts it can answer that, through an SMTP check, and that is what the paid product does.
- Upload the cleaned file as it is: CSVs up to 100,000 rows
- A real SMTP mailbox check on every row, with catch-all detection
- Small list? Starter at $9/mo covers 2,500 emails a month, cancel anytime
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.