Projected list size
Compound `pow` projection matches cohort spreadsheets—swap linear net adds or churn when you rebuild lifecycle scenarios in Calclet.
Example scenario
A publisher models list growth from 18,500 subscribers today using a 5.5% net monthly growth rate that nets acquisition against unsubscribes and spam complaints for the past baseline window. Over a 12-month horizon, compound projection yields roughly 35,172 estimated subscribers, implying about 16,672 net new subscribers versus day-zero inventory for this scenario. Operators compare optimistic versus conservative growth sliders before sizing sponsorship inventory and referral-program budgets.
Projected list size
Starting subs × (1 + monthly growth)^months
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How to use the projected list size
- Input subscribers today from your ESP’s active list definition aligned to paid sends or opted-in counts.
- Set net monthly growth (%) using observed net adds divided by starting subscribers from recent trailing months.
- Choose months ahead to match planning horizons such as annual sponsorship proposals or quarterly OKRs.
- Review estimated subscribers and net new subscribers versus today, then rerun conservative and aggressive growth scenarios.
Newsletter growth forecasting context
- Net versus gross signups
- Meaningful forecasts anchor net monthly growth so organic acquisition is reduced by churn and deliverability-driven losses rather than inflating with gross opt-ins alone.
- Compounding sensitivity
- Small sustained monthly growth rates compound materially over multi-quarter horizons, which is why scenario bands matter more than single-point optimism.
- Audience quality guardrails
- List size projections should pair with engagement benchmarks because inflated subscriber counts without opens and clicks do not convert to sponsorship yield.
Best use cases
- Forecasting and scenario planning
- Client education and pre-qualification
- Budget and performance decision support
Frequently asked questions
How do I estimate net monthly growth percentage from my ESP exports?
Pick a stable window, compute subscribers at period start and end, then solve for implied compound growth or approximate net growth as (ending minus beginning) divided by beginning divided by months for linear shortcuts.
Does this model handle list-cleaning events or bulk removals?
No automatically. Sudden hygiene purges reduce subscribers outside steady churn dynamics, so adjust starting subscribers or rerun forecasts after major list-cleaning actions.
Should paid acquisition subscribers be included in net growth?
Yes if your definition of net growth reflects all channels. Segment organic versus paid internally so projections reflect acquisition economics and subscriber quality differences.
Why can compound forecasts overshoot reality over 12 months?
Constant percentage growth assumes stationarity while acquisition channels saturate and churn mixes shift. Triangulate with cohort retention curves when stakes are high.
Glossary
Scenario modeling
Testing multiple assumptions to estimate possible outcomes before execution.
Commercial intent
User behavior indicating readiness to buy, subscribe, or request a quote.
Related calculators
Category: Email newsletter audience planningTopics: Subscriber forecast, Compound list growth, Publisher revenue planning
Last reviewed: 2026-05-07
Reviewed by: Calclet Growth Team