How we calculate

Updated October 3, 2026

Every cost and volume example on Pipe Playbook starts from the same five working numbers. They are ours: guidelines for planning, not vendor limits or benchmarks. Using the same set everywhere means a plan on one page matches the math on the next.

The five numbers

• 21 sending days a month. An average month has roughly 21 weekdays, and we plan cold sends for weekdays only.
• 30 sends per inbox per day. A deliberately low daily volume per mailbox, far under the limits vendors publish; it is our guideline, not a vendor rule.
• 4 inboxes per rep. Four mailboxes at 30 sends each give one rep 120 cold sends a day without any single mailbox carrying it all.
• 2 inboxes per domain. Two inboxes per sending domain keeps each domain near 60 sends a day, so trouble on one domain touches only two mailboxes.
• 5 touches per contact. An initial email plus four follow-ups on days 0, 3, 7, 10 and 14, inside Instantly’s 2026 recommendation of 4–7 touches, 3–4 days apart.

What they add up to

One inbox sends 30 × 21 = 630 emails a month. One rep with 4 inboxes sends 4 × 630 = 2,520 emails a month, which at 5 touches per contact is 2,520 ÷ 5 = 504 new contacts a month. Those inboxes sit on 4 ÷ 2 = 2 domains.

What is not on this list

Reply, meeting and win rates are starting assumptions you should replace with your own. Prices and vendor limits come from each vendor’s public pages and carry a date. The calculator starts from these numbers and lets you change any of them.

Questions or a number you would change: get in touch.