If you sell on Amazon using FBA, storage fees are one of the most consequential line items in your cost structure — and one of the least understood. Most sellers have a rough sense that Amazon charges for warehouse space. Fewer understand that there are actually three distinct fee types stacked on top of each other, that two of them are triggered by inventory behavior rather than just volume, and that a product sitting in an Amazon fulfillment center for nine months can accumulate fees that erase its entire margin before a single unit is sold.
This article breaks down each of the three storage fee types in plain terms, shows you exactly how the numbers work using a real product example, and gives you the framework to calculate what slow-moving inventory is actually costing you month by month. The goal is not to alarm you — it is to make sure you are working with accurate numbers rather than finding out the hard way.
Amazon updates its fee schedule every January. All figures in this article reflect the 2026 FBA fee structure effective January 15, 2026, with the fuel and logistics surcharge that took effect on April 17, 2026. Always verify current rates in Seller Central before making sourcing or inventory decisions.
The monthly base storage fee is the foundational charge — the rent you pay Amazon for the physical space your inventory occupies in their fulfillment network. It is calculated per cubic foot of space your products take up, based on daily average volume across the month, and it applies to every unit you have in FBA regardless of how long it has been there or how fast it is selling.
Amazon measures the volume of each product in its packaged, ready-to-ship state — not the volume of the shipping carton you sent to the warehouse. A product that measures 10 inches by 8 inches by 4 inches occupies 0.185 cubic feet (length × width × height, divided by 1,728 to convert cubic inches to cubic feet). That number is multiplied by the monthly storage rate and the number of units stored.
The rate varies by season and product size tier. Standard-size products — which covers the majority of consumer goods sold on Amazon — are charged at two different rates depending on time of year. Oversize products follow the same seasonal structure but at lower per-cubic-foot rates because they are calculated on actual cubic footage, which is already higher in absolute terms.
Monthly base storage rates (standard-size, 2026)
| Period | Standard-size | Oversize | Dangerous goods (standard) |
| January – September (off-peak) | $0.78 / cu ft | $0.56 / cu ft | $0.99 / cu ft |
| October – December (peak) | $2.40 / cu ft | $1.40 / cu ft | $3.63 / cu ft |
Source: Amazon Seller Central, effective January 15, 2026.
The Q4 jump is significant. Standard-size storage triples in cost between September and October. For a brand that sends in heavy inventory ahead of the holiday season and does not sell through it by December 31, January arrives with a warehouse full of products that just spent three months at premium rates.
According to industry seller surveys, 32% of FBA sellers say storage fees are their biggest unexpected cost. The Q4 rate spike catches first-year sellers off guard because most fee calculators only show non-peak rates.
Take a product — a small wellness supplement in a standard-size bottle — with dimensions of 3 inches × 3 inches × 5 inches. Packaged, it occupies about 0.026 cubic feet. You have 500 units sitting in Amazon’s fulfillment center from February through March.
Monthly base fee: 500 units × 0.026 cu ft × $0.78 = $10.14 per month. That is the floor — what you pay just for the space, with no complications. For most sellers with reasonable inventory turnover, this is the only storage fee that ever applies. The problems start when products stop moving.
The storage utilization surcharge is less talked about than the other two fees, but for brands with slower-moving inventory or large catalog volumes, it can be the one that causes the most confusion on a monthly invoice. It was introduced by Amazon to discourage sellers from treating FBA warehouses as cheap long-term storage — essentially, to penalize brands whose inventory-to-sales ratio is too high.
The surcharge applies when two conditions are both true. First, your average daily inventory volume in Amazon’s fulfillment centers is at or above 25 cubic feet. Second, your storage utilization ratio — calculated as your average daily inventory volume divided by your average daily shipped volume over the trailing 13 weeks — exceeds 22 weeks. You can monitor your utilization ratio in the FBA Inventory tool in Seller Central, or track it via your Inventory Performance Index (IPI).
In plain terms: if you are shipping 10 cubic feet of product per week on average but storing 300 cubic feet in FBA, your utilization ratio is 30 weeks. That exceeds the 22-week threshold, and you will be charged a surcharge on the inventory volume above that threshold. The surcharge only applies to inventory aged more than 30 days — very recently sent shipments are excluded.
New sellers (first shipment within the past 365 days), individual account sellers, and anyone with an average daily inventory volume below 25 cubic feet are exempt from this surcharge entirely.
The surcharge is tiered based on your utilization ratio, and the tiers are different for off-peak and peak periods. For 2026, Amazon added more granular tiers at the high end — specifically to increase the penalty for sellers who are significantly overstocked relative to their sales velocity.
Storage utilization surcharge tiers (off-peak, January–September 2026)
| Utilization ratio (weeks of cover) | Surcharge per cu ft / month | Applies to… |
| Below 22 weeks | No surcharge | All sellers below threshold |
| 22 – 26 weeks | $0.44 / cu ft | Inventory above 22-week threshold |
| 26 – 36 weeks | $0.76 / cu ft | Inventory above 22-week threshold |
| 36 – 44 weeks | $1.16 / cu ft | Inventory above 22-week threshold |
| 44 – 52 weeks | $1.58 / cu ft | Inventory above 22-week threshold |
| 52 weeks or more | $1.88 / cu ft | Inventory above 22-week threshold |
Source: Amazon Seller Central 2026. Peak season (October–December) rates are higher. Dangerous goods are exempt.
The surcharge stacks on top of the base monthly storage fee — it does not replace it. A seller with a 30-week utilization ratio is paying both the $0.78 per cubic foot base rate and the $0.76 surcharge on excess inventory simultaneously, for a combined rate of $1.54 per cubic foot on the overstocked portion. Push that ratio above 52 weeks and the combined off-peak rate hits $2.66 per cubic foot — before Q4 even begins.
What makes the utilization surcharge particularly unforgiving is that it is a ratio problem, not just a volume problem. You can have a relatively modest amount of inventory in absolute terms and still trigger it — if your sales velocity has slowed down enough relative to what you are holding. A brand that launched aggressively, sent in three months of stock, and then watched sales plateau is not a brand with a warehouse problem. It is a brand with a ratio problem. Amazon is not charging you because you have too much inventory. It is charging you because you have too much inventory relative to how fast you are selling it. That distinction matters because the fix is not necessarily to remove product — sometimes accelerating sell-through is faster, cheaper, and better for your listing’s ranking history than pulling units out.
The aged inventory surcharge is where slow-moving inventory becomes genuinely expensive. It is a separate, additional monthly fee that begins once your inventory has been sitting in Amazon’s fulfillment network for more than 181 days. It applies on top of — not instead of — the base monthly storage fee, and it escalates in tiers the longer inventory sits.
Until 2023, Amazon’s long-term storage penalties kicked in at 365 days. That gave sellers roughly a year to figure out what to do with a slow-moving product before the punitive fees started. Amazon then moved the threshold to 271 days. In 2026, it moved again — down to 181 days, which is just under six months. Sellers who built their inventory planning around a nine-month or twelve-month window and have not updated their models are now being hit by surcharges they did not anticipate.
The practical implication: any product that has been in FBA since mid-October is already past the 181-day mark as of mid-April. If you have not checked your aged inventory report recently, now is the time.
The aged inventory surcharge is more granular than most sellers expect. Amazon does not charge a single flat rate for anything over 181 days — the rate steps up every 30 days across eight tiers, and the jump between the 241–270 day tier and the 271–300 day tier is where things get seriously expensive. The full schedule is published in Amazon’s aged inventory surcharge help page. The table below reflects the rates effective January 16, 2026. Note that clothing, shoes, bags, jewelry, and watches are exempt from the 181–270 day tiers — surcharges for those categories begin at 271 days.
Aged inventory surcharge rates (standard-size products, from January 16, 2026)
| Days in FBA | Surcharge per cu ft / month | Minimum per unit charge |
| 0 – 180 days | No surcharge | — |
| 181 – 210 days* | $0.50 / cu ft | — |
| 211 – 240 days* | $1.00 / cu ft | — |
| 241 – 270 days* | $1.50 / cu ft | — |
| 271 – 300 days | $5.45 / cu ft | — |
| 301 – 330 days | $5.70 / cu ft | — |
| 331 – 365 days | $5.90 / cu ft | — |
| 366 – 455 days | $6.90 / cu ft | $0.30 / unit (whichever is greater) |
| 456 days or more | $7.90 / cu ft | $0.35 / unit (whichever is greater) |
Source: Amazon Seller Central, effective January 16, 2026. * Excludes clothing, shoes, bags, jewelry, and watches — surcharges for those categories begin at 271 days.
The structure here is worth reading carefully. From 181 to 270 days, the surcharge climbs gradually — $0.50, then $1.00, then $1.50 per cubic foot. Painful, but manageable. Then at 271 days it jumps to $5.45 per cubic foot — more than three and a half times the previous month’s rate — and continues climbing through $5.70 and $5.90 before crossing into the $6.90 tier at 366 days. The 271-day mark is the real cliff. By the time a product has been sitting for nine months, the monthly aged surcharge alone on even a modest volume of stock exceeds what most sellers paid in total storage costs during the product’s first six months.
To make this concrete, take a product with a wholesale cost of $15 and a retail price of $25. It is a standard-size item — a small household accessory — with packaged dimensions of 6 inches × 4 inches × 3 inches, which gives it a volume of 0.042 cubic feet. You have 200 units in FBA. The product launches in February and sells well initially, but velocity drops through spring. By month seven, sales had stopped entirely.
Here is what the storage fees look like month by month using 2026 rates, assuming all 200 units remain unsold from month seven onward with no removals or liquidation. Base fee calculations use $0.78 per cubic foot for January through September and $2.40 per cubic foot for October through December. Aged surcharges use the rates from Amazon’s official table above.
Monthly storage fees — 200 units at 0.042 cu ft each (total 8.4 cu ft), no sales from month 7 onward
| Month | Days in FBA | Base fee | Aged surcharge | Monthly total | Cumulative |
| Feb | 1 – 28 | $6.55 | — | $6.55 | $6.55 |
| Mar | 29 – 59 | $6.55 | — | $6.55 | $13.10 |
| Apr | 60 – 89 | $6.55 | — | $6.55 | $19.65 |
| May | 90 – 120 | $6.55 | — | $6.55 | $26.20 |
| Jun | 121 – 150 | $6.55 | — | $6.55 | $32.75 |
| Jul | 151 – 180 | $6.55 | — | $6.55 | $39.30 |
| Aug | 181 – 210 | $6.55 | $4.20 ($0.50/cu ft) | $10.75 | $50.05 |
| Sep | 211 – 240 | $6.55 | $8.40 ($1.00/cu ft) | $14.95 | $65.00 |
| Oct | 241 – 270 | $20.16 | $12.60 ($1.50/cu ft) | $32.76 | $97.76 |
| Nov | 271 – 300 | $20.16 | $45.78 ($5.45/cu ft) | $65.94 | $163.70 |
| Dec | 301 – 330 | $20.16 | $47.88 ($5.70/cu ft) | $68.04 | $231.74 |
| Jan (yr 2) | 331 – 360 | $6.55 | $49.56 ($5.90/cu ft) | $56.11 | $287.85 |
| Feb (yr 2) | 361 – 390 | $6.55 | $57.96 ($6.90/cu ft) | $64.51 | $352.36 |
Base fee = 200 units × 0.042 cu ft × storage rate. Aged surcharge = 200 units × 0.042 cu ft × applicable tier rate. Off-peak base rate: $0.78/cu ft (Feb–Sep). Q4 base rate: $2.40/cu ft (Oct–Dec). Aged surcharge rates from Amazon Seller Central. All figures rounded to two decimal places.
The numbers in the first six months barely register — $6.55 a month, easy to ignore. That is exactly the problem. The surcharge clock starts ticking quietly at month seven, and through August and September it is still manageable. Then October arrives. The Q4 base rate triples to $2.40 per cubic foot at the same moment the product crosses into the 271-day tier, where the aged surcharge leaps from $1.50 to $5.45 per cubic foot. November’s total fee is more than ten times what it was in July. By the end of the first year, this batch of 200 units has generated $287.85 in storage fees — on inventory that cost $3,000 to source and has generated nothing in revenue since month seven. By month 13, the cumulative fees have crossed $350.
The point is not the absolute dollar amount — it is the trajectory. A seller who checks their aged inventory report in July and takes action has options. They can run a promotion, create a bundle, drop the price to accelerate sell-through, or explore off-Amazon channels that let inventory remain in FBA while generating sales elsewhere. A seller who does nothing watches those options narrow with each passing month, and by November they are paying more in one month’s storage fees than the product earns in margin on a good sales day. And this example assumes no utilization surcharge. If this product sits alongside other slow-moving inventory in a larger catalog, that surcharge adds another layer on top of every number in the table above.
Amazon adjusts its FBA fee schedule annually, typically announcing changes in the fourth quarter for implementation in January of the following year. The 2026 changes are worth knowing specifically because several of them affect storage costs in ways that caught sellers who were not paying close attention.
The most significant 2026 storage change is the addition of a new aged inventory surcharge tier at 456 days or more, at $7.90 per cubic foot or $0.35 per unit — whichever is greater. This sits above the previous highest tier of $6.90 per cubic foot at 366–455 days. The storage utilization surcharge also gained new granular tiers at 44–52 weeks and 52+ weeks for 2026, with rates of $1.58 and $1.88 per cubic foot respectively. And a 3.5% fuel and logistics surcharge was added to all FBA fulfillment fees effective April 17, 2026 — this applies to fulfillment rather than storage directly, but it affects the overall cost calculation for any product still in FBA.
The best practice is to check Amazon’s official fee schedule at the start of each year and run your unit economics with the new numbers before they take effect. The FBA fee schedule on Seller Central is the authoritative source — third-party summaries (including this article) can lag actual implementation dates or miss nuances in how fees apply to specific product categories.
Your Inventory Performance Index, or IPI score, is Amazon’s internal measure of how efficiently you manage your FBA inventory. It factors in your excess inventory ratio, your sell-through rate, your stranded inventory levels, and your in-stock rate on high-velocity items. Sellers with scores above 400 have essentially unlimited storage capacity. Sellers below 400 can face capacity restrictions that limit how much new inventory they can send into FBA — which creates a compounding problem if slow-moving inventory is already occupying the space. You can monitor your IPI score in the FBA Inventory dashboard in Seller Central. It updates weekly, and the trend matters as much as the absolute number.
There is a direct connection between IPI score and storage fees. A low score is both a symptom of inventory management issues (slow sales, excess stock, stranded listings) and a cause of additional operational constraints. Brands that manage their IPI proactively — by clearing aging inventory before it crosses the 181-day threshold rather than after — tend to operate with lower effective storage costs and fewer capacity surprises.
Knowing what you are paying is not the same as knowing what to do about it. The three fee types covered in this article — base storage, utilization surcharge, and aged inventory surcharge — each respond to different inventory behaviors, and the right response depends on your specific situation: how fast your product moves, what your margin structure looks like, how many units are sitting in FBA, and how long they have been there.
Most sellers who run into trouble with storage fees do not lack awareness. They lack a decision framework for what to do once they realize a product has stopped moving. By the time November’s invoice arrives and the aged surcharge has multiplied by a factor of ten compared to July, the range of good options has already narrowed significantly. The goal of understanding the fee structure is not to track costs after the fact — it is to recognize the warning signs early enough that you still have leverage.
The worked example in this article ends at month 13 with $352 in accumulated fees on a batch of 200 units that originally cost $3,000 to source. That number is not catastrophic in isolation. What makes it damaging is the combination: the capital tied up in unsold inventory, the ongoing fees compounding monthly, the opportunity cost of what that warehouse space and that cash could be doing elsewhere, and the effect of a stagnant product on the health of the broader catalog in Amazon’s eyes.
In the next article in this series, we take the same product and run the numbers on what those fees actually do to the profit margin — month by month, through the break-even point and beyond. We also look at the opportunity cost side of the equation, because the real cost of slow-moving FBA inventory is almost always larger than the storage line on your invoice suggests. Read the next article in this series →
One option worth understanding before you get there is what Onlihub makes possible for brands in exactly this situation. The conventional response to slow-moving FBA inventory is to choose between unpleasant options: liquidate at 5 to 10 cents on the dollar through Amazon’s own program, pay removal fees and handle logistics yourself, or keep paying storage fees and hope sales recover. Each of those paths means either absorbing a significant loss or kicking the problem down the road.
Onlihub works differently. Instead of removing inventory from FBA, brands list their products through Onlihub’s retailer network — which includes sellers on eBay, Shopify stores, and other sales channels. When a retailer’s customer places an order, Amazon’s Multi-Channel Fulfillment ships it directly from the FBA warehouse where the inventory already sits. The product moves at a real market price, not a liquidation price. No removal orders. No new warehouse. No interruption to the brand’s Amazon channel, which remains restricted for resellers.
For a brand watching the storage fee clock tick on 200 units of a product that has slowed down on Amazon, this is not a last resort — it is a parallel channel that can be activated before fees become a crisis rather than after. The inventory that was generating nothing is now generating sales. The fees that were accumulating are now offset by revenue. And the brand retains control over pricing, channel restrictions, and product presentation throughout.
If you want to understand how this works in practice — including how brands set minimum prices, how orders flow through MCF, and what the economics look like compared to liquidation — the next articles in this series cover it in detail. Or you can explore how it works directly at onlihub.com.
