FBA Storage Fee Calculator
What is slow-moving stock costing me every month?
Your numbers
Result
Monthly storage cost
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How this is calculated
FBA storage is charged per cubic foot per month, with surcharges applied to inventory that ages past set thresholds. This calculator turns your dimensions and dwell time into a monthly cost and, more usefully, a per-unit cost.
- Cubic feet per unit = (length × width × height) ÷ 1728
- Total cubic feet = cubic feet per unit × units stored
- Monthly storage cost = total cubic feet × monthly rate
- Storage cost per unit = monthly storage cost ÷ units stored
- Cost over dwell = monthly storage cost × expected months in warehouse
What to make of the number
Storage is a slow leak rather than a shock, which is exactly why it gets ignored. A unit costing $0.20 a month looks trivial, but held for nine months instead of three it quietly consumes $1.20 of margin — often more than the difference between a profitable and a marginal product.
Frequently asked questions
How is FBA storage calculated?
On the volume the packaged unit occupies, measured in cubic feet, multiplied by the monthly rate and the time in the warehouse. Dimensional weight is not used for storage — it is used for fulfilment fees.
What is the aged inventory surcharge?
An additional fee applied per unit to inventory held beyond set ageing thresholds. It is designed to discourage long-term storage, and it is the clearest signal that a SKU should be repriced or removed.
Do storage rates change seasonally?
Yes. Peak-season rates are significantly higher, typically running from around October into January. Budget for it if you hold seasonal inventory through Q4.
Should I use a removal order for slow stock?
Often yes. Compare the cost of removal or disposal against the storage and surcharge cost of holding the unit until it sells. Once the projected holding cost exceeds the removal cost plus the margin you would earn, removing it is the better decision.
How can I reduce storage cost?
Reduce packaged dimensions, since volume drives the fee. Ship smaller quantities more often, and clear slow movers before they cross an ageing threshold. Packaging redesign is frequently the highest-return fix.
Do the research before you commit inventory
SkuMath shows you the math. Helium 10 supplies the live Amazon data those calculations need as inputs — product demand, keyword volume, competitor reviews and profit tracking.
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