Storage fees are one of the most misunderstood costs in the Amazon FBA fee structure. Many sellers plan around fulfillment fees and referral fees but treat storage as an afterthought. That is a costly mistake. For slow-moving inventory, storage fees can erode margins faster than any other charge Amazon levies. In 2026, with the expanded aged inventory surcharge tiers and the storage utilization surcharge, understanding exactly how storage fees work is more important than ever.
This guide covers every storage-related fee Amazon charges in 2026, shows you exactly how each one is calculated, and gives you actionable strategies to minimize your storage costs.
How Amazon Calculates Storage Volume
Before diving into rates, you need to understand how Amazon measures the space your inventory occupies. Amazon charges storage fees based on daily average volume, measured in cubic feet.
The volume for each unit is calculated using the product's dimensions when properly packaged and ready to ship. Amazon measures the length, width, and height of each unit, rounds up to the nearest whole inch on each dimension, then calculates:
Volume per unit = (Length x Width x Height) / 1,728
The divisor of 1,728 converts cubic inches to cubic feet. Amazon then multiplies this by the number of units stored on each day and averages across the month to determine your total billable volume.
Monthly Storage Fees: Standard Rates
Amazon charges monthly inventory storage fees for all units stored in its fulfillment centers. The rates differ by time of year and product size tier. These fees are charged between the 7th and 15th of the month following the storage period.
Standard-Size Products
| Period | Rate per Cubic Foot | Notes |
|---|---|---|
| January – September | $0.78 | Non-peak / off-peak season |
| October – December | $2.40 | Peak / holiday season (3x higher) |
Oversize Products
| Period | Rate per Cubic Foot | Notes |
|---|---|---|
| January – September | $0.56 | Lower rate per cubic foot, but items are larger |
| October – December | $1.40 | Peak season (2.5x higher) |
Worked Example: Monthly Storage Cost
Suppose you sell a standard-size product packaged in a box measuring 10" x 8" x 4". You keep an average of 500 units in Amazon's warehouse during March.
- Volume per unit: (10 x 8 x 4) / 1,728 = 0.185 cubic feet
- Total volume: 500 x 0.185 = 92.6 cubic feet
- March rate (off-peak): $0.78 per cubic foot
- Monthly storage fee: 92.6 x $0.78 = $72.23
If those same 500 units were stored in November instead:
- November rate (peak): $2.40 per cubic foot
- Monthly storage fee: 92.6 x $2.40 = $222.24
That is a $150 difference for the same amount of inventory. This is why smart sellers adjust their inventory levels heading into Q4 — you want products selling, not sitting.
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Try the Free FBA Calculator →Aged Inventory Surcharge (Long-Term Storage Fees)
In 2026, Amazon's aged inventory surcharge replaces the former long-term storage fee. Instead of a single penalty at the 365-day mark, Amazon now applies tiered surcharges starting at just 181 days. This change significantly increases the cost of holding slow-moving inventory.
| Inventory Age | Surcharge per Cubic Foot | Surcharge per Unit (minimum) |
|---|---|---|
| 181 – 210 days | $1.50 | $0.50 |
| 211 – 240 days | $3.80 | $0.50 |
| 241 – 270 days | $5.45 | $0.50 |
| 271 – 300 days | $7.12 | $0.50 |
| 301 – 330 days | $8.90 | $0.50 |
| 331 – 365 days | $10.68 | $0.50 |
| 365+ days | $6.90 + $0.15/unit | $0.15 |
Amazon calculates inventory age using a FIFO (first-in, first-out) method based on the date units were received at the fulfillment center. The surcharge is assessed on the 15th of each month. Items are eligible for the surcharge based on the snapshot of inventory on that date.
How Costly Can It Get?
Let's take the same product from our earlier example (0.185 cubic feet per unit) and assume 100 units have been sitting for 280 days.
- Regular monthly storage: 100 x 0.185 x $0.78 = $14.43
- Aged inventory surcharge: 100 x 0.185 x $7.12 = $131.72
- Total monthly cost for those 100 aged units: $146.15
If those units have a landed cost of $5 each (total $500 in inventory), you are paying nearly 30% of the inventory's value per month just in storage. After two months at that rate, you would have been better off giving the products away.
Storage Utilization Surcharge
Amazon introduced the storage utilization surcharge to discourage sellers from holding excessive inventory relative to their sales velocity. This surcharge applies when your storage utilization ratio is high — meaning you use a lot of warehouse space compared to how much you sell.
The storage utilization ratio is calculated as:
Ratio = Average daily inventory volume (cubic feet) / Average daily shipped volume (cubic feet)
A ratio above 26 weeks triggers the surcharge for standard-size products. For oversize, the threshold is also 26 weeks. The surcharge ranges from $0.10 to $0.69 per cubic foot on top of your standard monthly storage fee, depending on how far above the threshold you fall.
| Utilization Ratio (Weeks of Cover) | Standard-Size Surcharge | Oversize Surcharge |
|---|---|---|
| 0 – 26 weeks | No surcharge | No surcharge |
| 26 – 30 weeks | $0.10/cu ft | $0.10/cu ft |
| 30 – 36 weeks | $0.24/cu ft | $0.20/cu ft |
| 36 – 40 weeks | $0.42/cu ft | $0.35/cu ft |
| 40+ weeks | $0.69/cu ft | $0.60/cu ft |
This surcharge is calculated at the ASIN level and is applied based on the average ratio during the assessment period. Newer sellers (those with professional accounts for fewer than 39 weeks) are exempt.
Your IPI Score: The Storage Gatekeeper
Amazon's Inventory Performance Index (IPI) is a score from 0 to 1,000 that measures how efficiently you manage FBA inventory. While it does not directly change your storage fee rates, it determines whether Amazon limits how much inventory you can send in.
As of 2026, sellers with an IPI below 350 face storage volume limits. If your IPI drops below this threshold at the quarterly check, Amazon will cap the total cubic feet of inventory you can store, potentially preventing you from restocking popular items during high-demand periods.
Amazon calculates your IPI based on four factors:
- Excess inventory percentage: how many of your ASINs have more inventory than Amazon recommends based on forecasted demand.
- Sell-through rate: units sold and shipped over the past 90 days divided by average units in stock.
- Stranded inventory percentage: inventory in FBA warehouses that is not linked to an active listing (and therefore cannot sell).
- In-stock rate for replenishable ASINs: how often your FBA products are in stock and available for purchase.
A healthy IPI score (above 500) keeps your storage unrestricted and signals to Amazon that you are an efficient seller. Scores between 350 and 500 are acceptable but leave you little room for error. Below 350, you face real operational constraints.
9 Strategies to Reduce Your FBA Storage Costs
1. Monitor Inventory Age Religiously
Check the Inventory Age report in Seller Central weekly. This report shows exactly how many units sit in each age bucket (0-90, 91-180, 181-270, 271-365, 365+). Set alerts for any SKU approaching the 181-day mark and take action before the aged inventory surcharge kicks in.
2. Create Removal Orders Before Surcharges Hit
If inventory is approaching 181 days and is not selling, create a removal order. Amazon charges $1.04 per standard-size unit to ship it back to you (or $0.34 to dispose). That is almost always cheaper than paying months of aged surcharges. You can then try to sell the product through other channels, bundle it with faster sellers, or discount it heavily on Amazon.
3. Use Amazon Outlet and Deals
Amazon's Outlet program lets you offer deep discounts on slow-moving inventory directly within Amazon's ecosystem. Similarly, running a Lightning Deal or a 7-Day Deal can accelerate sales velocity on aging stock. The deal fee ($150 for a Lightning Deal) is often far less than cumulative storage surcharges.
4. Optimize Your Packaging
Since storage is charged per cubic foot, reducing your product's packaged dimensions directly reduces fees. Review whether your packaging has unnecessary empty space. A product packaged in a 12" x 10" x 6" box that could fit in a 10" x 8" x 4" box reduces storage volume by 55%, cutting your per-unit storage cost nearly in half.
5. Ship Smaller, More Frequent Replenishments
Instead of sending 6 months of inventory at once, send 4-6 weeks of supply at a time. This keeps your warehouse utilization low, reduces your exposure to aged inventory surcharges, and improves your IPI score. The trade-off is higher inbound shipping costs, so run the numbers to find the optimal replenishment frequency for each SKU.
6. Plan Q4 Inventory Carefully
October through December storage rates are 2.5 to 3 times the off-peak rate. Send Q4 inventory in September to minimize the days you pay peak rates. At the same time, do not overstock — unsold Q4 inventory will start accumulating aged surcharges by March.
7. Fix Stranded Inventory Immediately
Stranded inventory is product sitting in Amazon's warehouse that cannot sell because its listing is suppressed, inactive, or deleted. You pay storage fees on stranded inventory, but it generates zero revenue. Check the Stranded Inventory report regularly and resolve listing issues within 24 hours.
8. Use Amazon Warehousing & Distribution (AWD)
Amazon Warehousing & Distribution is a bulk storage program with lower rates than standard FBA storage. You send large quantities to AWD facilities, and Amazon automatically replenishes your FBA inventory as needed. AWD storage rates are approximately $0.48 per cubic foot per month — 38% cheaper than standard off-peak FBA storage. This is especially valuable for products with predictable demand.
9. Adjust Pricing to Improve Velocity
Sometimes the cheapest way to reduce storage costs is to lower your price by a few percent and increase sales velocity. An item generating $2 in profit that sells 50 units per month is more profitable than the same item at $3 in profit selling 10 units per month, especially once you factor in the storage fees those slow-selling units accumulate.
Calculate Your Exact FBA Fees
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Try the Free FBA Calculator →Storage Fees vs. Fulfillment Fees: Where Does Your Money Go?
For the average seller with good inventory management, storage fees account for roughly 3-7% of total FBA costs. Fulfillment fees (pick, pack, ship) make up the lion's share at 50-65%, with referral fees covering the remaining 30-40%.
However, for sellers with poor inventory management — particularly those holding products past the 181-day mark — storage costs can balloon to 20-40% of total FBA costs. This is where sellers go from profitable to unprofitable without realizing it, because the monthly surcharges compound and the damage only shows up when you run a detailed P&L by SKU.
Key Takeaways
- Monthly storage fees are manageable for products that sell within 90 days: roughly $0.15 to $0.50 per standard-size unit per month during off-peak.
- The aged inventory surcharge starting at 181 days is the fee that destroys margins. Treat 180 days as a hard deadline to move or remove inventory.
- Peak season (October-December) storage rates are 2.5 to 3 times the off-peak rates. Plan inventory levels accordingly.
- Keep your IPI above 400 to avoid storage limits, and above 500 for maximum flexibility.
- Storage costs are volume-based, not weight-based. Reducing packaging dimensions is one of the highest-ROI optimizations you can make.