Amazon storage, aged inventory and low-inventory fee estimator
This Amazon storage fee calculator estimates what one SKU costs to hold this month and what aging will add.
Amazon charges for space every month, charges more from October to December, adds a surcharge once units have been stored for 181 days or more and charges a low-inventory-level fee when stock runs too lean. That leaves a narrow window between too little and too much. Enter your units, dimensions and the rates on your own Seller Central fee pages to see where a SKU sits.
What this Amazon storage fee calculator estimates
Monthly storage for the SKU, the aged inventory surcharge by age band, an estimate of the low-inventory-level fee, the total per SKU and per unit, a 6-month projection as units age into higher bands and a "remove or hold" note when the next band's monthly cost exceeds what it would cost to remove the units.
The inputs
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Units per SKU
and unit dimensions in inches: cubic feet per unit = length × width × height ÷ 1,728.
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Size tier
standard or oversize, which use different storage rates.
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Month
January to September or October to December. Storage costs more in the fourth quarter.
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Your storage rate per cubic foot
for that tier and month, from your Seller Central fee page.
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Units by age band
0 to 180 days, 181 to 270, 271 to 365, 366 to 455 and over 455 days. Aged surcharges start at 181 days, and 2026 added a top tier for stock held more than 15 months (Seller Labs, vendor, updated Aug 3, 2026).
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Your aged surcharge rate for each band
, from your fee page. Where Amazon lists both a per-cubic-foot and a per-unit charge for a band, enter both and the estimator applies the one your fee page says applies.
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Days of supply at FBA
, units shipped in the period and your low-inventory-level fee per unit from Fee Preview.
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Removal fee per unit
, for the remove-or-hold note.
The formula and method
- Cubic feet per unit = L × W × H (inches) ÷ 1,728
- Monthly storage = units × cubic feet per unit × your monthly rate for the tier and month
- Aged surcharge per band = units in the band × cubic feet per unit × the band's rate (or units × the per-unit rate, where that applies)
- Low-inventory-level fee estimate = units shipped in the period × your fee per unit, shown only when days of supply is under 28
- Total = storage + aged surcharges + low-inventory estimate
- Remove or hold = compare next month's storage and surcharge for the oldest band with units × removal fee
The low-inventory-level fee applies only when both your 30-day and 90-day historical days of supply are below 28 days, and Amazon applies exemptions, so treat that line as a flag to check, not a bill. Seller Labs (vendor, Aug 3, 2026) reports that from Jan 15, 2026 the fee also covers small and large bulky items, does not apply to oversize, apparel or hazmat products and exempts new FBA products for their first 180 days of sales history.
Worked example
Illustrative · sample figures. The rate used below is an example rate, not Amazon's; replace it with the rate on your fee page.
1,000 units of a 12 × 8 × 4 inch item: 384 ÷ 1,728 = 0.222 cubic feet each, 222 cubic feet in total.
| Line | Calculation | Result |
|---|---|---|
| Monthly storage at an example rate of $1.00 per cubic foot | 222 × $1.00 | $222 |
| Same month, if your fourth-quarter rate is three times higher | 222 × $3.00 | $666 |
| 200 of the units pass 181 days, example surcharge of $0.50 per cubic foot | 200 × 0.222 × $0.50 | $22.20 |
| Days of supply at FBA: 1,000 ÷ 25 a day | 40 days, no low-inventory flag |
The point of the example is the shape: storage scales with cubic feet, the fourth quarter multiplies it and surcharges stack on top once units age. A SKU that looks cheap to hold in March can cost several times as much per unit by November if it has not sold through.
Limitations
- It uses the rates you enter. Amazon publishes its rates in Seller Central, and they change; check them before you rely on the result.
- Amazon measures historical days of supply itself and applies exemptions. The low-inventory line is an estimate.
- Units age by received date per unit; the age bands here are your own estimate from the Inventory Age report.
- It does not include placement fees, inbound defect fees or removal order processing times.
Under every result: this estimate uses the figures you enter and published rates. It is not an audit, an offer or a promise of savings, sales or profit.
When does Amazon's aged inventory surcharge start?
Once units have been stored in a fulfillment center for 181 days or more, with higher tiers as they age further. For 2026 Amazon added a top tier for stock held more than 15 months (Seller Labs, vendor, Aug 3, 2026). Check the current rates in Seller Central.
When does the low-inventory-level fee apply?
Only when both your 30-day and 90-day historical days of supply are below 28 days, unless an exemption applies. Keeping at least 28 days of supply at FBA on steady sellers avoids it.
Is it cheaper to remove old stock than to keep it?
Sometimes. Compare next month's storage and surcharge for the oldest units with the removal or disposal fee per unit. If holding costs more and the units are unlikely to sell soon, removal usually wins.
See all free calculators.
Sources4 sources
- 01sellingpartners.aboutamazon.comOct 15, 2025; checked Oct 20, 2026Primary
- 02sellerlabs.comaged surcharge from 181 days, 2026 tiers, low-inventory-level fee scope; updated Aug 3, 2026; vendor; checked Oct 20, 2026Vendor
- 03supplychaindive.comJul 13, 2026; checked Oct 20, 2026Primary
- 04sellercentral.amazon.comAmazon staff, "Low-inventory-level fee further explained": fee only when both 30-day and 90-day historical days of supply are below 28 days; about 2023; checked Oct 20, 2026Primary
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