Email List Growth Calculator
Project where your email list lands months from now based on your sign-up rate and churn — and see whether you're actually growing or just refilling a leaky bucket.
| Month | Subscribers | Net |
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Growth is sign-ups minus the slow leak
It's easy to celebrate a month of strong sign-ups and miss that the list barely moved, because churn quietly subtracts from the total at the same time. A list of 10,000 losing 3% a month sheds 300 subscribers before a single new one is counted — so 300 sign-ups just keeps you flat. The larger your list grows, the larger that monthly leak becomes in absolute terms, which is why pure acquisition eventually hits a ceiling. Modelling both numbers together, as this calculator does, shows you the real trajectory instead of the flattering half of it, and it makes the case for treating retention as a growth lever rather than an afterthought.
The cheapest subscriber is the one you keep
Acquiring a new subscriber costs money and effort — ads, lead magnets, landing pages. Keeping an existing one mostly costs relevance. That asymmetry is why high-churn lists are so expensive to grow: you're paying to refill a bucket faster than it drains. The fix is rarely more sign-up forms; it's sending mail people actually want, segmenting so the right message reaches the right person, and pruning dead weight before it hurts your deliverability. Drop your churn by a single percentage point and the same sign-up rate suddenly compounds into meaningfully faster growth, month after month.
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Frequently asked questions
What is email list churn?
Churn is the rate at which you lose subscribers — through unsubscribes, spam complaints, and hard bounces from dead addresses. It's the leak in the bucket: even a healthy sign-up rate can produce flat growth if churn is high enough to cancel it out.
What's a healthy net growth rate for an email list?
There's no universal number, but most lists should aim for net positive growth every month after accounting for churn. A common rule of thumb is to keep monthly churn (unsubscribes plus bounces) under about 0.5% per send; above that, focus on list hygiene and relevance before chasing more sign-ups.
Should I remove inactive subscribers?
Yes. Subscribers who never open or click drag down your deliverability, because mailbox providers read low engagement as a quality signal. Run a re-engagement campaign, then suppress or remove those who stay cold. A smaller, engaged list outperforms a large, dormant one on both inbox placement and revenue.