Net, not just gross
See Substack and Stripe fees separately, then account for your own monthly business costs.
Free planning tool · No account required
See what your Substack could actually earn.
Model paid conversion, pricing, churn, growth, and the fees between gross revenue and what reaches you.
Live, editable forecast Calculations stay on this device
A balanced planning case. Every assumption remains editable.
Your assumptions
Audience and pricing
Subscribers choosing annual
Annual plans lower payment frequency and processing cost.
Growth and retention
Audience growth / month
Paid churn / month
Fees and own costs+
Defaults use the published US baseline: 10% Substack fee, 2.9% + 0.30 card processing, and 0.7% recurring Billing fee. Edit these for your country and Stripe account.
Current run rate
Estimated monthly take-home
$1,521
$18,257 annual run rate
250
Paid subscribers
$1,800
Gross monthly
$279
Estimated fees
You keep before own costs84.5% of gross
Month 12 take-home
$1,844
303 paid subscribers
Year-one take-home
$20,041
Before taxes and your own costs
Work backward
What would your income goal take?
847
paid subscribers needed
16,940
free audience needed
Includes your $150 monthly costs and current fee, price, plan-mix, and conversion assumptions.
Price sensitivity
Price and conversion move together.
Compare monthly take-home across nearby price and conversion cases. Annual pricing moves by the same percentage.
| Monthly price | 3.8% conversion | 5.0% conversion | 6.3% conversion |
|---|---|---|---|
| $6.40 | $908 | $1,210 | $1,513 |
| $8 | $1,141 | $1,521 | $1,902 |
| $9.60 | $1,374 | $1,832 | $2,291 |
Forecast ledger
The numbers behind the curve.
Paid subscribers retain month to month after churn; only newly added free subscribers convert at the selected rate.
| Month | Free audience | Paid | Gross | Fees | Take-home |
|---|---|---|---|---|---|
| Now | 5,000 | 250 | $1,800 | −$279 | $1,521 |
| 3 | 5,624 | 258 | $1,861 | −$288 | $1,573 |
| 6 | 6,327 | 270 | $1,944 | −$301 | $1,643 |
| 9 | 7,117 | 285 | $2,050 | −$317 | $1,733 |
| 12 | 8,005 | 303 | $2,182 | −$338 | $1,844 |
A real retention model
Forecast new audience growth and paid churn over 12, 24, or 36 months.
A goal you can work backward from
Turn a monthly income target into the paid and free audience required to support it.
How the forecast works
A planning model, with the assumptions left visible.
This calculator is intentionally more conservative than multiplying your audience by a conversion rate forever. Paid readers can churn, new free readers convert over time, and fees follow each plan's billing frequency.
Start with today
Current paid subscribers are estimated from your free audience and conversion rate. Monthly and annual plans are blended into a monthly-equivalent run rate.
Grow the free audience
Each month, the free list grows by your selected rate. Only those newly added readers are converted into new paid subscribers.
Retain the paid base
Existing paid subscribers carry forward after monthly churn. This makes retention as visible as acquisition.
Subtract the real fees
The model removes the Substack fee, Stripe percentage and fixed processing fees, and the recurring Billing fee before showing take-home.
Useful enough to plan with. Honest enough not to promise.
Your result is an estimate, not financial or tax advice. Currency conversion, refunds, regional card pricing, taxes, gifts, discounts, and app-store purchases can change real payouts.
Does Substack really take 10%?+
Substack currently publishes a 10% fee on each paid transaction. The calculator uses that as the default and lets you edit it in the advanced assumptions.
Which Stripe fees are included?+
The default US baseline includes 2.9% plus 0.30 per card transaction and a 0.7% Stripe Billing fee for recurring payments. Your region, payment method, and account pricing may differ.
Why is annual revenue shown monthly?+
The main forecast uses monthly-equivalent revenue so monthly and annual plans can be compared. Annual subscribers pay in larger, less frequent cash installments, so your real payout calendar will be lumpier.
What conversion rate should I use?+
Use your own historical rate when possible. If you are pre-launch, compare the Steady, Base, and Growth cases and treat the range as more useful than any single answer.
Does Stackflyer store my numbers?+
No. The calculator runs in your browser. It does not require an account or send these planning assumptions to Stackflyer.
The forecast needs a publication