First Sale Fees / Field guide

How the fee calculations work

Read the formulas, assumptions and limits behind each estimate.

By Masato Ishioka · Updated 2026-09-15

One month, one price, one currency

The main calculator models paid sales of one product at a constant USD price. Monthly subscriptions are charged once. Percentage fees apply to product revenue. Payment-processing charges use the percentage and fixed amount you enter.

Revenue = product price × paid sales
Platform fee = monthly subscription + revenue × platform rate
Processor estimate = revenue × processor rate + paid sales × fixed processing fee
After modeled fees = revenue − platform fee − processor estimate

The example processing rate is editable

The initial 2.9% plus $0.30 is an illustration, not a quote for your country, card mix or provider account. The same input is applied to every row so the platform fee difference remains visible. Replace it with your own rate. If the plans need different processors, calculate each setup separately.

What the estimates leave out

Taxes, refunds, disputed payments, cross-border charges, currency conversion, payout fees, payment minimums, optional video hosting, email add-ons and other subscriptions are excluded. Payment fees may apply to a tax-inclusive total; that is not modeled here. Results are rounded to cents for display, so rounding at the processor's transaction level can produce small differences.

Annual discounts are not included in the main calculator. All recurring prices used there are monthly-billing list prices. A result below zero means the modeled fees exceed the modeled revenue; it is not a prediction of a negative bank payout.

Cost does not establish suitability

The lowest fee row is not an overall product ranking. Course capacity, subscriber limits, integrations, accessibility, support and the work involved in migrating can change the decision. Verify those separately.

Evidence and review

The source links and review date appear on the relevant pages. Fee thresholds and worked examples are our calculations. We have not measured conversion rates, user earnings or search traffic for this publication.