Free FBA tool
FBA Storage Fee Calculator
Your numbers
Monthly storage / unit
$0.87
Off-peak (Jan-Sep). In the Q4 peak it jumps to $2.40 per unit, about 2.76x, for the same 1 cu ft standard-size unit.
Size category
Standard
1 cu ft (Large Standard)
Off-peak / mo
$0.87
Jan-Sep rate
Peak / mo
$2.40
Oct-Dec (2.76x)
Cost to hold
$1,614.00
200 units x 4 mo
Cost to hold assumes the full 200 units sit in storage every month (Amazon bills the month-end snapshot). As you sell through, your real bill is lower, so treat this as the worst case for carrying the batch.
Inventory Hero
Catch aging inventory before the surcharge hits
This page estimates storage from the size you type. Inventory Hero tracks how long each SKU's units have actually sat in FBA, so you see real storage cost building up and get warned before units reach 181 days into the surcharge or drift into the Q4 peak.
- Real storage cost per SKU, not a size estimate
- Aging alerts before the 181-day surcharge applies
- Spot slow movers before they carry into Q4 peak rates
No credit card required.
How FBA storage fees are calculated
Monthly storage
Monthly fee = cubic feet x the seasonal rate for your size category
Cubic feet = length x width x height divided by 1,728. Standard-size pays $0.87 per cubic foot off-peak and $2.40 in Q4; oversize pays $0.56 and $1.40. Multiply by the units held and the number of months, billing each month at its own seasonal rate.
Rates reflect Amazon's 2026 US monthly storage schedule (effective January 2026). Amazon can adjust fees, so confirm against Seller Central before you commit a shipment.
Worked example
An 18 x 12 x 8 inch unit weighs 5 pounds, so it is Large Standard (standard-size) and measures exactly 1.0 cubic foot. You send 200 units and hold them for 4 months starting in September.
- Off-peak monthly: 1.0 cu ft x $0.87 = $0.87 per unit (January to September)
- Q4 peak monthly: 1.0 cu ft x $2.40 = $2.40 per unit, about 2.76x
- Across the 4 months: September is off-peak ($0.87), then October, November, December are peak ($2.40 each) = $8.07 per unit
- Total for 200 units: $8.07 x 200 = $1,614, most of it from the three Q4 months
Subtract storage from your margin in the FBA profit calculator, and size each order so less inventory sits through Q4 with the EOQ calculator.
Key terms
- Cubic feet
- The volume Amazon bills storage on: length x width x height in inches, divided by 1,728. A smaller pack size directly lowers the storage fee, because you are charged on the space the unit occupies.
- Standard vs oversize
- The two storage rate classes. Small and Large Standard units are standard-size ($0.87 / $2.40 per cubic foot); Bulky and Extra-Large units are oversize ($0.56 / $1.40). The split comes from the unit's size tier, which is set by its dimensions and weight.
- Peak storage period
- October through December, when Amazon's monthly storage rate more than doubles (about 2.76x for standard-size). Inventory that sits unsold through Q4 is where storage cost does the most damage.
Frequently asked questions
How much is the Amazon FBA storage fee?
Monthly storage is billed per cubic foot: in 2026 standard-size is $0.87 per cubic foot off-peak (January to September) and $2.40 in the Q4 peak (October to December); oversize is $0.56 off-peak and $1.40 in peak. For an 18 x 12 x 8 inch unit (1.0 cubic foot), that is $0.87 per unit per month most of the year and $2.40 in Q4.
Why is FBA storage so much higher in Q4?
Amazon raises monthly storage rates from October through December because warehouse space is scarcest in the holiday run-up. For standard-size that is about a 2.76x jump ($0.87 to $2.40 per cubic foot); for oversize it is 2.5x ($0.56 to $1.40). Inventory that sits through Q4 without selling is where storage quietly eats margin, so the calculator splits your holding period into off-peak and peak months.
How is the FBA storage fee calculated?
Storage = your unit's volume in cubic feet (length x width x height divided by 1,728) times the monthly rate for its size category (standard or oversize), for each month it is stored. Size category comes from the size tier: Small and Large Standard are standard-size; Bulky and Extra-Large are oversize. Multiply by the number of units and the months held to get the total holding cost.
Does this include the aged-inventory surcharge and other storage fees?
No. This calculates the base monthly storage fee. It does not include the aged-inventory surcharge (an extra charge on units stored 181 days or more), the storage-utilization surcharge (an extra fee when your account holds a lot of inventory relative to your recent sales), or the low-inventory-level fee (which can apply when your historical days of supply runs below 28 days). Those depend on age and velocity; the calculator focuses on the monthly fee every unit pays.
How do I lower my FBA storage costs?
Sell through faster so units spend fewer months in storage, send less inventory at a time (smaller, more frequent shipments), and avoid carrying slow movers into the Q4 peak when rates more than double. Reducing a unit's packed dimensions also cuts the cubic feet you are billed on. For a slow mover already in stock, compare the cost to hold against a removal order (roughly $0.97 per standard unit): pulling it before three months of Q4 peak storage plus the aged surcharge is often cheaper than holding. Tracking days of supply per SKU tells you which units are about to age into the surcharge.
Inventory Hero
Plan Q4 orders around real storage cost
Storage is a planning decision, not just a fee. Inventory Hero rolls each SKU's real storage cost into true per-unit profit and days-of-supply, so when you size Q4 orders you know exactly how much margin every extra month in the warehouse costs, before you ship it.
14-day free trialNo credit card required.
Embed this calculator
Free to use on your own site or blog. Paste this snippet where you want the calculator to appear. It keeps a small credit link back to Inventory Hero.
<iframe src="https://www.inventoryhero.ai/embed/fba-storage-fee-calculator?utm_source=embed&utm_medium=iframe" title="FBA Storage Fee Calculator by Inventory Hero" width="100%" height="720" style="border:1px solid #e5e5e5;border-radius:16px;max-width:680px" loading="lazy"></iframe>
<p style="font:13px/1.5 system-ui,sans-serif;text-align:center;margin:8px 0 0"><a href="https://www.inventoryhero.ai/tools/fba-storage-fee-calculator">FBA Storage Fee Calculator</a> by Inventory Hero</p>See all our free Amazon FBA calculators.