The Email Warmup Calculator is a free tool that builds a day-by-day sending schedule to help you warm up an email account before cold outreach. It works without a Hunter account, and it's a good starting point if you're not ready for Inbox Protection yet.
What the calculator does
Enter your email provider, whether the account is new, and your current and target daily sending volume. The calculator generates a ramp-up schedule that gradually increases your sending volume each day until you reach your target, along with an estimated completion date.
Enter your details
Go to the Email Warmup Calculator.
Select your email provider ("Google Workspace," "Microsoft 365," or "Other").
Indicate whether the account is new or already sending.
Enter your current and target daily sending volume.
Choose a start date and a ramp pace ("Conservative" or "Standard").
Read your schedule
The calculator returns a summary of your ramp-up — days to target, completion date, total warm-up emails, and your safe daily volume — plus a chart showing the ramp over time.
Below that, a day-by-day table breaks the same schedule down by date, with the emails to send that day, the cumulative total, and any milestones (like "Week 1 complete" or "Target reached").
💡 If your target is above 50 emails/day from a single inbox, the calculator flags this and suggests spreading volume across multiple accounts.
Export or save your schedule
Download the schedule as a CSV file.
Download it as a calendar file (.ics) to add a daily reminder for each sending day.
Enter your email to receive the schedule.
👉 The calculator doesn't send anything or connect to your Hunter account — you follow the schedule manually, at your own pace.
When to use Inbox Protection instead
The calculator plans a manual ramp-up you run yourself. If you'd rather not send warm-up emails manually, Inbox Protection automates the same ramp — sending warm-up emails and generating real replies for you.
👉 See How to warm up an email account before sending cold emails for a full comparison of the manual and automated options.