Newsletter Growth Calculator

How does the projection work?

The calculator subtracts your monthly churn rate from your monthly growth rate to get a net rate, then applies that rate to the subscriber count once for each month, compounding. 2,500 subscribers at 5% growth and 2% churn become 2,500 × 1.03 raised to the 12th power, which rounds to 3,564. The rounding happens once at the end.

What do growth and churn refer to?

Both are percentages of the list at the start of each month. Growth is new subscribers divided by current subscribers, and churn is lost subscribers divided by current subscribers. Because both scale with list size, the model assumes new signups rise as the list grows. If you actually add a roughly fixed number each month, this overstates the long-term curve.

What does “Current net monthly adds” mean?

It is the starting list multiplied by the net rate, rounded, and it describes month one only. With 2,500 subscribers and a net rate of 3% it shows 75. It is not an average across the projection: in the default 12-month run the list adds more than 75 a month by the end. It goes negative when churn exceeds growth.

Is “Projected annual revenue” what I will earn over the period?

No. It is the end-of-projection monthly revenue multiplied by 12, which is an annualised run rate at the final subscriber count. The default 12-month run gives 3,564 subscribers, $3,564.00 a month and $42,768.00 a year. The revenue actually collected while growing from 2,500 to 3,564 would be lower.

What happens if churn is above 100% or the list shrinks?

Churn is capped at 100%, so the list cannot go below zero. Before that cap a churn rate of 150% made the multiplier negative, which flipped the subscriber count between positive and negative values from one month to the next. With the cap, 1,000 subscribers, no growth and 150% churn project to 0 after three months.

How long can the projection be?

The period is rounded to a whole number and limited to between 1 and 120 months. Blank or invalid values fall back to 12. Negative growth, churn or revenue entries are treated as zero, so enter a decline as a higher churn rate rather than a negative growth figure.

Does revenue per subscriber change as the list grows?

No. One value is multiplied by the final subscriber count. Real newsletters often earn from only a minority of readers through paid tiers, sponsorships or affiliate links, so divide your total monthly revenue by your total list to get a single figure that represents all of them.