TinyAffiliate Tools

Marginal revenue calculator

A quick marginal model for SaaS + affiliates. See how much net revenue you keep from one additional purchase after discount codes, affiliate commission, Stripe fees, and expected refunds.

Last updated: 2026-03-21

Inputs (per customer)

This is a quick marginal model: how much net revenue and profit you keep from one additional purchase after discounts, affiliate commission, Stripe fees, and expected refunds.

Notes

  • Refund rate is treated as an expected-value haircut (simple but useful).
  • If you’re modeling subscriptions, run this per first payment (then extend with LTV separately).

Outputs (expected)

Gross after discount$49.00
Expected collected (after refunds)$46.55
Expected affiliate commission$9.31
Expected Stripe fees$1.63
Marginal revenue kept$35.61
Marginal profit (after variable cost)$35.61
Take-home rate (net / collected)76.5%

How to use this

• If marginal profit is low, reduce commission, reduce discount, or improve refund rate.

• Use this when negotiating creator deals: you need net margin room for fixed sponsorship fees.

• Pair it with an ROI model for acquisition channels.

Related tools

Use marginal revenue to sanity-check unit economics, then use ROI to compare channels.

Marketing ROI calculator →Commission calculator →Stripe fee calculator →