Inventory Carrying Cost Calculator Methodology
Estimates annual carrying cost from inventory value, storage percentage, capital cost, obsolescence, and turn rate.
Amazon FBA is active. Other marketplace modules stay marked as planned until audited.
Estimates annual carrying cost from inventory value, storage percentage, capital cost, obsolescence, and turn rate.
Fee basis: source-state planning estimate; modeled fee basis is under review and not a Seller Central reconciliation. Last source-state review: 2026-06-07.
planning estimate. Planning estimate — fee basis is source-dated and under review, not a Seller Central reconciliation.
Modeled in the estimate
- monthly storage fee — Planning estimate: this fee basis is not independently primary-source verified (secondary_only) and its source date has passed. Treat as directional, not a Seller Central reconciliation. report_mode
Explicitly excluded
- low inventory level fee — Excludes Amazon low-inventory-level fees (depend on your days-of-supply, not modeled here).
- aged inventory surcharge — Excludes aged-inventory surcharges (depend on how long stock has been stored).
Primary source register: Amazon fee schedules · Amazon Revenue Calculator.
Formula
annual_carrying_cost = inventory_value × (storage_pct + capital_cost_pct + obsolescence_pct); per_turn_cost = annual_carrying_cost / annual_turns
Includes
- Average inventory value
- Storage cost percentage
- Cost of capital
- Obsolescence/shrinkage where available
- Per-turn cost
Excludes
- Exact FBA cubic-foot storage bill
- Aged inventory surcharge by age band
- Low-Inventory-Level Fee
- Inventory placement fee
- Insurance if not included in storage/carrying assumptions
2026 fee-category audit
| Fee component | Status |
|---|---|
| Q4 storage seasonal spike | included in inventory storage assumptions |
| Aged Inventory Surcharge | explicitly excluded |
| Low-Inventory-Level Fee | explicitly excluded |
| Inbound Placement Service Fee | explicitly excluded unless user enters |
Diagnostic output: Margin status, largest carrying-cost driver, per-turn cost, and sensitivity to storage/capital-rate changes.
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