Margin Leak Calculator Methodology
Estimates per-order margin after product cost, platform fees, and shipping, then compares the result to a target margin.
Amazon FBA is active. Other marketplace modules stay marked as planned until audited.
Estimates per-order margin after product cost, platform fees, and shipping, then compares the result to a target margin.
Fee schedule/source date: generic marketplace fee model verified 2026-05-08.
Primary source register: Amazon fee schedules · Amazon Revenue Calculator.
Formula
actual_margin = selling_price - platform_fees - product_cost - shipping_cost; target_price = (product_cost + shipping_cost) / (1 - platform_fee_pct - target_margin_pct)
Includes
- Product cost
- Platform-fee percentage
- Shipping cost
- Target margin gap
- Signed per-order margin
Excludes
- Inventory carrying cost
- Returns
- PPC/ACoS
- Coupons and promos unless included in price
- Sales tax/VAT
- Chargeback and fraud losses
- Marketplace-specific fee permutations
2026 fee-category audit
| Fee component | Status |
|---|---|
| Coupons and promotional discounts | explicitly excluded unless user enters |
| PPC / ACoS impact | modeled in break even ad spend |
| Returns Processing Fee | modeled in return cost planning |
| Sales tax / VAT pass-through math | explicitly excluded |
| 2026 baseline FBA fulfillment-fee schedule | included or not applicable |
Diagnostic output: Margin status, largest cost leak, target-margin price floor, max COGS, and margin sensitivity to fee changes.
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