A useful model.
With visible assumptions.

The calculation, in plain language

Retained orders

Acquired orders × (1 − full-return rate).

Seller revenue

(Price after seller discounts + shipping proceeds received) × retained orders ÷ (1 + VAT included in price). Platform-funded vouchers are reimbursed, not deducted twice.

Contribution

Seller revenue − platform charges − creator payouts − ads − product cost − fulfilment − return processing − other per-order costs.

Margin

Contribution ÷ retained seller revenue × 100. Not markup, and not net business profit after overhead and tax.

Maximum creator commission

Contribution before creator payouts ÷ commissionable revenue × 100. This is a break-even ceiling, not an offer recommendation or a target-margin ceiling.

Maximum CPA at target margin

(Contribution before ads − target margin × retained revenue) ÷ acquired orders. The free health check uses a 25% reference; Pro CPA and creator tools let you choose the target.

Forecast

Current contribution × (1 + chosen monthly volume growth)^(month − 1). Revenue and costs scale together. This is a scenario, not a demand prediction.

The break-even price is found by repeatedly recalculating the same inputs at different selling prices. Category thresholds can make fees discontinuous; for unusual or high-value products, verify the result against your exact fee schedule. Read the worked $40 product example.

Costs and returns

• Creator commission uses item price after seller discounts, excluding included output tax in the US. The unreversed-creator-fee setting adds returned orders whose creator commission cannot be recovered. Ads, fulfilment and other per-order costs apply to all acquired orders.
• Full refunds after delivery, one SKU per order. Reusable inventory is editable: new models start at 0% recovery; older saved models retain their previous 90% assumption, now visible. Recovered stock is inventory value, not cash.
• US refund administration is modelled as 20% of the original referral fee, capped at $5 per returned order. This assumes one SKU unit per order; the official policy applies its cap by SKU type and has exceptions. Multi-unit and partial-refund settlements need a separate reconciliation.
• Commission, transaction, fixed, service and growth fees have separate overrides. Platform vouchers remain in the transaction base. Thailand and Philippines transaction charges remain after a post-delivery refund; Thailand growth fees also remain. Brazil shipping programme fees apply only when enrolled. Verify waivers, Mall status and other programmes in your account.
• VAT included in price is removed from retained revenue, not from gross commission bases where the policy includes it. US fee bases exclude that tax. Enter costs consistently net of recoverable VAT; input-tax credits are not calculated. Use 0% for tax-exclusive prices.
• Contribution excludes business overhead, income tax, financing and duties unless allocated explicitly. The Pro cash planner separately models 30 days of uniform sales, upfront inventory and launch costs, operating-payment timing and the full sale-to-usable-cash delay. It does not count recovered inventory as cash or fund restocking.

A default return rate or scenario growth rate is an example, not a market benchmark. Use mature cohorts from your own shop. See the return-cost sensitivity example.