Amazon storage utilization surcharge calculator
Once you've been on FBA for a year, Amazon adds a storage utilization surcharge to your monthly storage fees when you hold more than 22 weeks of supply. Enter the volume you store and ship a day (both on your FBA Dashboard): the calculator gives your storage utilization ratio, its band, what the surcharge costs a month, and how much stock to sell down or remove to get under 22 weeks.
Surcharge = 600 cu ft × 70% aged over 30 days × $0.76. To get under 22 weeks, store 138 cu ft less (or ship that much more over the 13 weeks).
How Amazon works it out
- Storage utilization ratio = your average daily inventory volume over the past 13 weeks ÷ your average daily shipped volume over the same 13 weeks ÷ 7: how many weeks your stock would last. Amazon works it out separately for standard-size and oversize, leaves out inventory pending removal, and uses the ratio on the last day of the month for that month's fees.
- Who pays: Professional sellers whose first shipment to a US fulfillment center was more than 365 days ago, who store 25 cubic feet or more a day in that size tier, and whose ratio is above 22 weeks.
- What's charged: the surcharge rate for the band, per cubic foot, on inventory aged over 30 days, on top of the base monthly storage fee.
| Storage utilization ratio | Standard-size surcharge | Oversize surcharge |
|---|---|---|
| 22 weeks or less | None | None |
| 22 to 28 weeks | $0.44 a cu ft | $0.23 a cu ft |
| 28 to 36 weeks | $0.76 a cu ft | $0.46 a cu ft |
| 36 to 44 weeks | $1.16 a cu ft | $0.63 a cu ft |
| 44 to 52 weeks | $1.58 a cu ft | $0.76 a cu ft |
| 52 weeks or more | $1.88 a cu ft | $1.26 a cu ft |
Base monthly storage fees for comparison: standard-size $0.78 a cubic foot from January to September and $2.40 from October to December; oversize $0.56 and $1.40. From Amazon's monthly inventory storage fees page in Seller Central (2026).
In the example, 600 ÷ 3 ÷ 7 = 28.6 weeks: the 28 to 36 weeks band, so $0.76 a cubic foot on the 70% older than 30 days, $319.20 on top of a $468.00 base fee in July. Storing 138 cu ft less would bring it under 22 weeks.
How to get under 22 weeks
- Send smaller shipments more often: the restock calculator sizes each order to the weeks of supply you choose.
- Sell slow stock down with a lower price, a coupon or more ad spend before it ages, or remove it: the removal fee calculator compares removal, disposal and liquidation.
- Watch the products that have stopped selling: they count in the volume stored but add nothing shipped.
Storage utilization questions
Where do I find my numbers?
On the FBA Dashboard in Seller Central, which shows the average daily inventory volume, shipped volume and the ratio for each size tier. The Monthly Storage Fees report shows the ratio used for past months.
Does it apply to all my inventory?
Only to inventory aged over 30 days, and only in the size tier whose ratio is above 22 weeks. Inventory in the FBA New Selection program's free storage, and products auto-replenished through Amazon Warehousing and Distribution that qualify for the waiver, are left out.
What does all my storage cost?
The FBA storage fee calculator adds the base fee, this surcharge and the aged inventory surcharge for one product.
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