FBA capacity limits: what they are, how Amazon sets them and how to plan around them

FBA capacity limits decide how much of your inventory Amazon will hold at any one time. On March 1, 2023, Amazon replaced weekly restock limits and quarterly storage limits with a single monthly limit per storage type, measured in cubic feet. The storage types are standard-size, oversize, extra-large, apparel and footwear, each with its own limit, and Amazon's capacity help page says capacity cannot be moved from one type to another. Apparel and footwear are assigned by listing category; every other product is sorted by its dimensions and weight. Capacity for dangerous goods, such as flammables and aerosols, is handled separately. The rules here come from Amazon's US seller pages and forum posts; other marketplaces can differ.

How is FBA capacity usage calculated?

Amazon sets the limit. Your job is to track usage against it. Usage counts two things: stock already sitting in fulfillment centers, and open shipments on the way. A shipment you created and never sent still uses space until you cancel it.

Capacity used = on-hand volume + open inbound volume (cubic feet, per storage type)

Headroom = monthly limit − capacity used

Unit volume = length × width × height in inches ÷ 1,728 (cubic inches in a cubic foot)

Take a standard-size limit of 1,500 cubic feet, with 900 on hand and 350 in open shipments. Headroom is 250 cubic feet. What that buys depends on the product:

Same headroom, nearly five times the units for the smaller SKU. That is why a replenishment plan written in units can be impossible to ship.

How does Amazon set your limit?

An Amazon staff post splits accounts three ways:

• Individual accounts: fixed at 15 cubic feet, not eligible for increases.
• Professional accounts active in FBA for less than 39 weeks: no capacity limits.
• Professional accounts active in FBA for 39 weeks or more: limits based on IPI and sales performance.

For those established accounts, Amazon's help page says the limit is shaped by your IPI score along with historical sales, seasonal peaks, forecasts for your ASINs, new selection, scheduled deals, shipment lead time and its own fulfillment center capacity. The staff post says a consistently strong IPI earns more space, scaled to how much you sell and how much room Amazon has.

You see the limit and your usage in Capacity Monitor at the bottom of the FBA dashboard, with a tab for each storage type and a table of limits for the next three months. Limits are typically announced in the fourth week of the month, in Capacity Monitor and by email: the coming month's limit is confirmed, the next month's estimate is reaffirmed or adjusted, and a new estimate is added for the month after. If you need more room, Capacity Manager lets you ask for extra space and name the most you will pay as a reservation fee. Amazon reviews free space about twice a week and fills requests from the highest bid per cubic foot down. Requests cannot cover the current period, and Capacity Manager says the extra space may open up to a month early so you can ship into it. Performance credits earned from your sales can offset the fee; Amazon's 2023 Q&A with the FBA team says requests go to the highest reservation fee per cubic foot first.

How many sales does a Capacity Manager request need to pay for itself?

It depends on your total limit, not on how much extra space you buy. Capacity Manager pays a $0.15 credit per dollar of FBA sales, but the sales it counts are all your shipped sales in that storage type during the period, prorated by the share of your total limit the extra space represents. Amazon's own example: 500 extra cubic feet on a 1,000 limit is a third of the new 1,500 limit, so a third of $105,000 in sales qualifies, which earns up to $5,250.

The extra cubic feet cancel out of the arithmetic, which leaves one line:

Break-even FBA sales in that storage type = fee per cubic foot × new total limit ÷ 0.15

The fees below are made up to show the method, not market rates; Amazon does not publish a going rate on this page. The limits are Amazon's Example 1.

So compare the break-even line with what that storage type sold in the same month last year. Below it, you pay the balance after the period ends. Amazon also says the fee you pay may be lower than your maximum, since every request granted that week takes that week's lowest fee, and later grants at a lower fee adjust yours down. Only FBA sales count, and a grant can be cancelled only in narrow cases, such as a confirmed limit that comes in above your estimate.

What blocks a shipment when you think there is room?

Two different checks can stop a shipment, and they have different fixes. Amazon's capacity page covers the first group, and its product restriction page covers the rest.

Amazon's restriction page still describes stranded stock as having no active offer, while its stranded inventory page now also counts search-suppressed stock and says a shipment with a stranded ASIN will not be processed. Neither says outright that suppressed stock triggers the block, so check a suppressed SKU before you plan a shipment around it. The per-SKU plan for each block is in automated replenishment.

Does AWD have a capacity limit too?

Yes. Stock in AWD still sits outside FBA limits, but Amazon's AWD capacity page gives AWD a cap of its own, measured the same way: cubic feet of on-hand stock plus open shipments. We read it on November 7, 2026.

Your base allocation comes from your own AWD usage history, so, on our reading, a brand that used AWD lightly in 2026 and plans to lean on it in 2027 is the one most likely to come up short. Amazon reviews the allocation quarterly and shows it six weeks ahead. New sellers, and those inactive for six months, get a default that refreshes after 13 weeks of AWD history.

Above the base, a storage reservation holds at least 1,000 cubic feet at one facility for 4 to 26 weeks and must start at least three weeks after you ask. You can hold one for each facility type. At the East Coast base rate of $0.48, a 1,000 cubic foot reservation costs $504 a month from February 1 ($0.48 plus 5% is $0.504). If you fill half of it, you still pay $504, which works out to about $1.01 per cubic foot used. Both the capacity page and the reservation fee page start this billing on February 1. Amazon's 2027 fee overview mentions reservations with no date of its own, right after its March 1 sentence, so if one spans those dates, confirm it with Amazon. Our AWD capacity guide has the worksheet, the email checklist and the reservation arithmetic. See all the 2027 changes by date.

Why do capacity limits matter for operations and growth?

Capacity is a shared budget. Every SKU in a storage type competes for the same cubic feet, so one slow, bulky SKU can crowd out a best seller that is about to run out. Amazon blocks new shipments once on-hand stock plus open shipments exceeds the limit, and blocks any shipment whose units would push you over it, so new inbound for that storage type waits until space frees up.

Fees are a moving target. Amazon's 2023 rules charged an overage fee when on-hand stock alone ran over the limit, then in a 2024 peak-readiness post Amazon said it had dropped that fee from July 1, 2024. Check the current fee pages before you plan to run over.

The limit also looks forward. Because IPI is an input, inventory that sits unsold today can mean less space next month. And a launch or seasonal push that needs extra stock has to be planned against the estimated limit, not this month's.

What mistakes do sellers make with FBA capacity?

• Planning in units. Limits are in cubic feet. Convert every SKU before deciding quantities.
• Forgetting open shipments. Open shipments count toward usage. Stale or oversized shipments you never send still hold space until you cancel them.
• Treating storage types as one pool. Headroom in standard-size does nothing for an oversize SKU.
• Using FBA as the warehouse. Amazon says AWD inventory does not count against FBA storage limits, and AWD can replenish FBA automatically. A 3PL can hold buffer stock too. Check AWD's own cap before moving stock there.
• Assuming 2027 tiers leave storage types alone. From January 15, 2027, Amazon replaces extra-large with six oversize tiers, yet the capacity page still maps storage types to the old tiers and neither page says what happens to the extra-large limit. Watch the Capacity Monitor tabs when January limits arrive.
• Checking the limit once a month. Headroom moves every day as units sell, customer returns are received, removal orders are created (usage drops within 24 hours, even while pending) and shipments are created or cancelled.

How does Growth OS plan around capacity limits?

Ecomsellertool Growth OS runs on your own accounts and is built to keep a daily capacity ledger per storage type:

1. Usage. It pulls on-hand and inbound quantities from the SP-API FBA Inventory API, then converts them to cubic feet and groups them using the item volume and storage type Amazon reports for each SKU in the Manage Inventory Health report. Amazon's measurements, not your catalog's, decide usage.
2. Limits. The confirmed limit and the estimates from Capacity Monitor are entered or imported into the ledger when Amazon publishes them, so headroom is known before a shipment is planned.
3. Allocation. When space is tight, it ranks SKUs by days of cover and margin and gives headroom to the ones closest to a stockout.
4. Overflow. Units that do not fit stay in AWD or a 3PL as safety stock, and FBA inbound plans are drafted through the Fulfillment Inbound API (v2024-03-20) for approval.

The full planning logic is in automated replenishment, and the downstream risk is covered in stockouts.

Where should you start?

If capacity surprises you each month, or shipments get planned in units and cut back later, start with the free Quick Scan in the Ops Gap Diagnostic. It works from reports you upload, including an Inventory Ledger or Manage FBA Inventory report, and returns your top three Amazon operations gaps, each with a yearly dollar estimate. The paid Deep Diagnostic covers every channel you sell on. To see the base system first, look at Growth OS.

If shipment plans are still checked against capacity by hand, send us that routine as a project brief. We scope a workflow that compares planned shipments with your remaining FBA and AWD capacity and flags the gap before a shipment is created.