Enter SMS Growth Inputs
The page uses one main content column, while the form fields switch to three columns on large screens, two on smaller screens, and one on mobile.
Example Data Table
This sample mix shows how a marketing team might structure monthly acquisition channels before running the projection.
| Channel | Monthly Opt-ins | Estimated Monthly Spend | Typical Use |
|---|---|---|---|
| Website Popup | 320 | $0.00 | Collects subscribers from high-intent traffic. |
| Checkout Box | 180 | $0.00 | Captures buyers during purchase flow. |
| Keyword Campaign | 140 | $120.00 | Builds list from in-store and offline prompts. |
| Paid Social | 260 | $450.00 | Acquires subscribers from prospecting campaigns. |
| Organic Content | 110 | $0.00 | Turns blog and social visitors into subscribers. |
| Referral Flow | 70 | $65.00 | Rewards current subscribers for bringing new leads. |
Formula Used
1. Base monthly gross opt-ins
Base Gross Opt-ins = Popup + Checkout + Keyword + Paid + Organic + Referral
2. Month-specific opt-ins
Gross Opt-insm = Base Gross Opt-ins × (1 + Opt-in Growth Rate)m-1
3. Month-specific removals
Removalsm = Opening List × (Unsubscribe + Bounce + Complaint + Prune Rates) × (1 + Churn Change Rate)m-1
4. Net additions and ending list
Net Addsm = Gross Opt-insm − Removalsm
Ending Listm = Opening List + Net Addsm
5. Messaging cost
Monthly Cost = (Opening List × Messages per Month × Cost per SMS) + Platform Cost + Ad Spend + Other Tool Cost
6. Revenue and ROI
Revenue = Sends × Click Rate × Conversion Rate × Revenue per Conversion
ROI = (Total Revenue − Total Cost) ÷ Total Cost × 100
How to Use This Calculator
- Enter your current subscriber count and choose the number of months to project.
- Add expected monthly opt-ins by channel, including popup, checkout, keyword, paid, organic, and referral sources.
- Set your monthly removal rates for unsubscribes, bounces, complaints, and list pruning.
- Add cost assumptions, sending frequency, click rate, conversion rate, and revenue per conversion.
- Press Calculate Growth to see the results above the form, review the chart, and export CSV or PDF files.
FAQs
1. What does this calculator estimate?
It projects subscriber growth, removals, ending list size, messaging cost, conversion-driven revenue, and ROI across the months you choose.
2. Why are removals split into several rates?
Unsubscribes, bounces, complaints, and pruning affect list health differently. Tracking them separately helps identify whether growth problems come from targeting, data quality, or compliance pressure.
3. What is opt-in growth rate?
It increases or decreases future monthly acquisition volume. Use a positive value if acquisition improves over time, or a negative value if channel performance weakens.
4. What does churn change rate mean?
It adjusts removal pressure month by month. Rising churn can reflect list fatigue, weaker segmentation, or seasonal audience behavior.
5. Can I use this for budgeting?
Yes. The calculator combines fixed platform costs, ad spend, tool costs, and sending cost, so you can compare list growth against expected spend.
6. Why include click and conversion rates?
List growth alone does not show business impact. Click and conversion assumptions connect audience size to projected revenue and ROI.
7. What is a healthy output to watch first?
Start with net subscriber gain, overall churn rate, and cost per net subscriber. Those three metrics quickly reveal whether growth is efficient and sustainable.
8. Should I trust long-term projections exactly?
Treat them as planning estimates, not guarantees. Real campaigns change with seasonality, deliverability, promotions, creative quality, and audience behavior.