Calculator

Inbox Count Calculator

How many inboxes do you actually need — active, backup, and in warmup — based on your daily send target.

Your setup

200
202,000
25%
10%50%
20%
0%50%

Your inbox count

Active inboxes15/day each
14
Backup inboxes25% reserve
4
In warmup20% pipeline
3
Total inboxes
21
Domains neededmax 3 inboxes/domain
7

Estimated monthly cost

$126 – $315

Based on $6–15/inbox/month

Rule of thumb: Max 3 inboxes per domain. Keep at least 25% of your active pool as pre-warmed backup. If you need inboxes ready without a warmup period, WarmInboxes provides pre-warmed inboxes you can deploy same-day.