Amazon FBA Inventory Age & Surcharge Planner
Track the oldest-unit age, the entered aged-inventory threshold and the next monthly assessment date without inventing a fee amount. Inputs stay in your browser.
This tool plans inventory-age and assessment dates. It deliberately does not estimate a fee because marketplace rates, size tiers, exemptions and inventory snapshots change.
Context matters.
- Use the oldest affected inventory age shown by Amazon rather than a purchase-order or shipment-created date.
- Removal, disposal, liquidation and new-selection waivers have separate eligibility and cutoff rules.
Sources & scope
The calculation guide and this source trail show what the result means, where the rule came from and when it was last reviewed. This is source-and-calculation QA, not a claim of medical, legal, tax or other professional review; time-sensitive decisions still belong with the linked authority.
A visible path from input to answer.
Track the oldest-unit age, the entered aged-inventory threshold and the next monthly assessment date without inventing a fee amount. The page keeps the calculation scope and its limits beside the result so the output can be checked, copied or revisited.
- Read the record. The calculator uses Oldest unit received by FBA, Inventory review date, Aged-inventory threshold, Confirmed threshold (days) and Monthly assessment day and 1 additional field supplied in the form.
- Apply the scope. It applies the Amazon FBA U.S. inventory-age planning — Seller Central inventory and fee records control reference and the explicit date, unit and counting conventions shown in the result.
- Expose the checkpoints. Intermediate rows, warnings and timeline events stay visible; the emphasized row identifies the primary checkpoint when one exists.
This tool plans inventory-age and assessment dates. It deliberately does not estimate a fee because marketplace rates, size tiers, exemptions and inventory snapshots change.
- Current inventory age150 days
- Rule verificationNot confirmed
Calculation purpose: Track the oldest-unit age, the entered aged-inventory threshold and the next monthly assessment date without inventing a fee amount. This is a high-sensitivity reference output; the linked authority or qualified professional controls the final decision.
Calendar inputs use plain year-month-day semantics. Leap days, month ends, date-pair order and unsupported dates are checked before the result is shown.
Rule set 1.1.0 · Last reviewed 2026-08-22 · Next review due 2027-02-22. The source panel below contains the linked evidence.
What to know before using the result.
Does the calculator show my actual FBA surcharge?
No. It tracks inventory age and assessment timing only; marketplace, size, storage volume and current fee tables determine amounts.
Which receipt date should I use?
Use the oldest unit date shown by the current FBA inventory-age record for the SKU or inventory group being reviewed.
Why must I confirm the threshold?
Amazon fee thresholds and assessment practices can change by marketplace and year, so Seller Central is the live authority.