- Free cold email calculator
- Inbox and domain sizing
- Full cost breakdown, funnel and ROI
Free Cold Email Calculator (Cost and ROI)
Calculate your exact cold email outreach ROI before spending a dollar. Enter your campaign metrics to instantly calculate revenue potential, total costs, and profit margins.
Campaign Basics
Sending Infrastructure
Cost Assumptions
Funnel Assumptions
📊 The Funnel is sequential: positive replies (% of replies) → meetings booked (% of positive replies) → deals closed (% of meetings).
⚠️ This is a planning tool. Real-world performance depends on list quality, offer, copy, and deliverability.
Financial Summary
Unit Economics
Infrastructure Required
Plan a campaign before you buy a single domain. This cold email calculator works out the inboxes and domains you need, what they cost, how many replies and meetings to expect, and your return.
How many inboxes do you need for cold email?
Start from volume. Multiply prospects by emails per prospect to get total sends, then spread them across the sending days in your campaign. That gives a daily target.
Divide the daily target by a safe limit per inbox, around 30 to 50 cold emails a day, to get the inbox count. Then divide by 2 or 3 inboxes per domain to get the number of domains.
- About 30 to 50 cold emails per inbox per day
- 2 to 3 inboxes per domain
- Follow-ups count toward the daily limit
- Leave headroom for warm-up and replies
Plan for deliverability as well as volume
The calculator sizes your setup. These habits keep it working once you hit send.
Use secondary domains
Send cold email from lookalike domains so your main company domain stays protected.
Authenticate every domain
SPF, DKIM and DMARC on each one. Run the domain scanner before launch.
Warm up before sending
New inboxes need a few weeks of gradual volume before they carry a full daily load.
Verify the list
Bounces burn inboxes fast. Keep hard bounces well under 2%.
What to enter in the cold email calculator
| Input | What to enter | Tip |
|---|---|---|
| Prospects | Contacts in the campaign. | Count only verified emails. |
| Emails per prospect | First email plus follow-ups. | 3 to 4 is common. |
| Campaign days and sending days | Length of the campaign and days per week you send. | Weekdays only is a safe default. |
| Inboxes per domain and daily limit | How you spread volume. | Stay within 30 to 50 per inbox. |
| Domain, mailbox and manager costs | What you pay for infrastructure and people. | Include tools and warm-up. |
| Reply, positive, meeting and close rates | Your funnel conversion at each stage. | Use past campaign numbers if you have them. |
| Customer lifetime value | Revenue from one closed customer. | Use gross profit for a stricter ROI. |
Reading your cold email ROI
ROI compares the revenue from closed deals with the full cost of the campaign: domains, mailboxes, tools and the time of whoever runs it. If the number is thin, the biggest lever is usually the list, not the volume.
A better-targeted list lifts reply and meeting rates at every stage below it. Doubling sends on a weak list mostly doubles your cost and your spam complaints.
It takes your prospects, sequence length and sending schedule to find daily volume, then sizes inboxes and domains from your safe sending limits. Your costs and conversion rates produce the funnel, total cost and ROI.
Divide your daily sends by a safe per-inbox limit of about 30 to 50. For 450 emails a day at 30 per inbox, you need 15 inboxes, or 5 domains with 3 inboxes each.
Around 30 to 50 per warmed-up inbox is the common safe range. Push past it and spam placement rises. Scale by adding inboxes and domains instead of raising the limit.
Use your own past campaign data if you have it. If not, run a conservative and an optimistic version and plan around the conservative one.
Spreading volume across domains limits the damage if one domain's reputation drops. More than three inboxes on one domain concentrates risk and makes problems harder to isolate.
Further reading
- Google email sender guidelines Gmail requirements for authentication, spam rates and unsubscribe links.
- Yahoo sender best practices What Yahoo Mail expects from bulk and cold email senders.
- Google Postmaster Tools Free Gmail data on your domain reputation and spam rate.
Want the infrastructure built to these numbers?
We set up the domains, mailboxes, authentication and warm-up your plan calls for, then help you run the campaign.