Quick Answer
List growth is projected by adding new monthly signups and subtracting subscribers lost to churn each month, compounding forward. A list of 5,000 gaining 400 signups a month with 2% churn grows to roughly 5,300 after one month and continues climbing as long as signups outpace churn losses.
vs. Subscriber Value Calculator: this tool projects how many subscribers you’ll have over time. The Subscriber Value Calculator measures how much each subscriber is worth in revenue, not how many you have.
How the List Growth Calculator Works
Enter your current subscriber count, new signups per month, and monthly list loss rate โ the percentage of subscribers you expect to lose each month through unsubscribes, hard bounces, or other attrition. The calculator finds your break-even signup rate (the minimum signups needed just to stay flat), your net monthly growth, and your estimated subscriber lifetime, then compounds the same math forward to project your list size at 3, 6, and 12 months.
Because list loss applies to your current list size each month, the number of subscribers lost grows as your list grows, even at a constant loss rate โ this calculator models that compounding effect rather than a flat monthly loss.
Subscribers Lost = Current Subscribers ร List Loss Rate
Break-Even Signup Rate = Current Subscribers ร List Loss Rate
Net Monthly Growth = New Signups โ Subscribers Lost
Estimated Subscriber Lifetime (months) = 1 รท Monthly List Loss Rate
Tips for Using This Calculator Effectively
- Use your actual churn rate, not a guess. Most email platforms report unsubscribe rate directly โ pull it from recent months rather than estimating.
- Separate churn from list cleaning. If you manually remove inactive subscribers, that’s a deliberate list-health decision, not churn in the traditional sense โ model it separately if it’s a one-time event.
- Re-run this after any signup source change. A new lead magnet or paid acquisition channel can shift your signup rate significantly โ update the projection when your funnel changes.
- Pair with the Subscriber Value Calculator. A growing list is only valuable if each subscriber is also worth something โ check both together for the full picture.
Example Scenarios
5,000 subscribers, 400 new signups a month, 2% churn โ a healthy net gain that compounds to meaningful growth over a year.
10,000 subscribers with only 150 new signups a month against 1.5% churn โ net growth near zero, signaling a need for more acquisition.
A promotional push doubles signups temporarily, but churn also rises as less-qualified subscribers unsubscribe within weeks.
2,000 subscribers with no active signup source and 3% monthly churn โ a list that will meaningfully shrink over a year without intervention.
Frequently Asked Questions
What’s a normal email list churn rate?
Monthly churn between 0.5% and 2% is typical for actively maintained lists. Rates above 3-4% often signal list quality issues, poor list hygiene, or content that isn’t matching subscriber expectations.
Does churn include people who never unsubscribe but stop engaging?
This calculator models formal unsubscribes and hard bounces. Inactive-but-subscribed contacts are a separate list-health concern worth tracking alongside churn, since they inflate list size without adding value.
Why does my projected growth look faster than expected?
Compounding growth accelerates over time when net growth is positive, since each month’s larger base produces a larger number of new signups if your signup rate scales with list size, such as through referrals.
Should I count double opt-ins or all signups?
Use confirmed subscribers, whichever your platform counts as an active, deliverable contact โ this keeps your churn rate and growth projection consistent with what you’re actually paying to email.
Now that you know your growth trajectory, revisit the Email Open Rate Calculator to check how effectively you’re engaging the new subscribers you’re bringing in.