Cold Email Calculator
Run the funnel forwards from daily volume to booked meetings, or backwards from a meetings target to the sends and mailboxes it takes. With the mailbox safety check most calculators leave out.
Enter what you send today and see what comes out the other end of the funnel.
Volume
Sending capacity is a mailbox problem before it is a copy problem. Set these first.
Conversion rates
Defaults are conservative benchmarks for a verified mid-market list. Replace them with your own numbers as soon as you have 5,000 sends of data.
Funnel for the period
300 emails a day across 22 working days.
Mailbox load
You are short 4 mailboxes for this volume. Buy the inboxes before you buy more data: sending the same list through too few inboxes burns both.
How this works
The formula, and the denominator most people get wrong
Meetings equal sends times inbox placement times reply rate times positive reply share times the rate at which positive replies become calls. The trap is applying reply rate to sends instead of to delivered mail. If 15 percent of your volume lands in spam, a 3 percent reply rate measured on sends is really 3.5 percent of the mail that actually arrived, and every number downstream inherits the error. This calculator applies every rate to delivered mail, and it runs the same compounded rate in both directions, so the daily volume it gives you in reverse mode returns your meetings target when you type it back into forward mode.
Why 50 emails per mailbox per day is the wall
Mailbox providers score sending behaviour per inbox, not per campaign. Under about 30 a day a warmed mailbox on a healthy domain sits comfortably inside normal human volume. Between 30 and 50 you are relying on list quality and warmup to hold the line. Past 50 the reputation damage compounds, and it follows the domain long after you drop the volume back down. The fix is always horizontal: more mailboxes across more secondary domains, usually two or three inboxes per domain, never more sends per inbox. Budget around 10 dollars per mailbox per month for the domain, the licence, and warmup, before your sending tool.
Benchmarks worth using as a starting point in 2026
Reply rates have fallen every year that cold email has been automated, so plan low. On a verified list with genuine personalisation, expect 75 to 90 percent inbox placement, 1 to 5 percent total reply rate (3 percent is a good result, not a floor), 10 to 25 percent of those replies actually positive, and 40 to 60 percent of positive replies converting to a booked call. Compounded, that is one meeting per 400 to 800 sends in the middle of the range, and past 2,000 when the list is weak. Anything claiming a 10 percent reply rate is quoting a tiny hand-built list or counting out-of-office autoreplies. Open rate is in the tool for completeness only: privacy proxies inflate it, and it should never be the metric you optimise against.
Cost per meeting is the number to argue about
Tool and data spend divided by meetings booked gives you a floor, not the true cost, because it excludes the rep time spent handling replies. Compare it against your average deal value and win rate: if a meeting costs 200 dollars, you close one in five, and a deal is worth 8,000 dollars, then each deal costs 1,000 dollars to acquire and outbound pays for itself eight times over, so the constraint is capacity rather than economics. If the same maths gets you close to breakeven, adding volume makes the problem bigger. Fix the list and the offer first.