Profit Hawk
Free tool · For Amazon FBA sellers

FBA Capacity Usage Calculator
for Amazon sellers.

See how much of your Amazon FBA storage capacity is used, how many more units will fit, and whether your next shipment is going to land or get bounced.

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What question does this answer
“How much of my FBA capacity am I using, and how much more can I send?”
1

Your FBA capacity

Pull these numbers from your Capacity Manager in Seller Central. They're account-specific — we don't guess.

ft³
ft³
ft³
units
units

Capacity limits differ by storage type (standard-size vs. oversize) and by account. If you manage both, run this calculator once per storage type.

Shipment verdict
Fits comfortably

Shipment fits. You'll be at about 80% of capacity after it lands.

Capacity usage56% used today
In useThis shipment
Units that fit today
2,750units
After shipment
80%used
FBA capacity kit

Keep this 80% FBA plan inside your limit

Get a practical kit for modeling FBA capacity, identifying spillover units, and deciding what should move through FBA, AWD, or 3PL.

  • PDF of this calc — 80% utilized · 6,250 unit limit · 1,500 plannedInstant
  • Multi-SKU template — for ranking FBA capacity usage by productSheet
  • Extended calculator — live IPI + AWD/3PL spillover modelingTool
  • 5-day FBA playbook — capacity planning, one short email a dayCourse
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How it works

The math, in plain English.

Capacity planning is two divisions and a comparison. Hard part is using the right numbers, which is exactly why this tool asks you to pull them from Seller Central.

Remaining capacity =Limit −Current usage
ft³
Capacity Manager values. Pull both the limit and current usage in cubic feet directly from Inventory → Capacity Monitor in Seller Central. The same SKU mix can hit different limits across standard-size and oversize, so run the calculator per storage type.
÷ unit
Cubic feet per unit. Units that fit = remaining cubic feet ÷ cube per unit. For mixed shipments, divide the total shipment cube by total units to get a weighted average.
cover
Days of cover after shipment. Optional but useful: (current + inbound units) ÷ average daily sales. If that number runs past ~180 days, you're shipping aged-inventory exposure into the future even though the cube fits today.

Worked example

A standard-size FBA seller planning a routine restock.

Capacity limit2,500 ft³
Current FBA usage1,400 ft³
Remaining capacity2,500 − 1,400 = 1,100 ft³
Cubic feet per unit0.4 ft³
Units that fit1,100 ÷ 0.4 = 2,750
Proposed shipment1,500 units = 600 ft³
Post-shipment usage(1,400 + 600) ÷ 2,500 = 80%
Verdict
Fits comfortably
Watch out for

Common FBA capacity mistakes.

Capacity isn't usually the failure mode — assumptions about capacity are. These are the patterns we see most often when sellers overrun their limit.

01

Treating one capacity number as 'your' limit

Standard-size and oversize have separate limits. A seller who has plenty of room on standard but is maxed out on oversize will still get blocked from oversize inbound — even though 'total' capacity looks healthy.

Fix: Run this calculator separately per storage type. Use the right limit for the SKU you're shipping.
02

Sending the maximum that fits

Just because Amazon will accept it doesn't mean you should send it. Shipping right up to your cap leaves no slack for demand spikes, slower receiving, or surprise capacity changes.

Fix: Target 80–85% post-shipment utilization. Stage the rest at AWD or your 3PL.
03

Forgetting that received-but-not-listed units count

Units in FC receiving still take physical cube and count toward your usage. Big inbound deliveries can spike capacity faster than Capacity Monitor refreshes.

Fix: If you have a large PO landing this week, subtract it from remaining capacity before sending more.
04

Sending lots of slow movers because there's space

Filling FBA with C-tier SKUs because they fit is how aged inventory happens. Space alone isn't a reason to send — sell-through is.

Fix: Check days of cover. If post-shipment cover is over 90–180 days, send less.
05

Ignoring inbound velocity

Receiving times vary. A shipment that 'fits' in cubic feet today may not be checked in until weeks after it arrives, eating capacity that's technically still showing as available.

Fix: Plan capacity against inbound-eligible (in-route + in-receiving + on-hand), not just on-hand.
06

Using outdated capacity numbers

Amazon adjusts capacity allocations periodically. A limit you copied three months ago may not match what Capacity Monitor shows today.

Fix: Refresh the capacity number every time you plan a sizable inbound shipment.
When this calculator isn't enough

Great for one shipment.
Painful for a real PO calendar.

This tool sanity-checks one shipment against today's capacity. Planning a quarter of inbound across hundreds of SKUs and multiple storage types — that's where capacity decisions get hard.

  • Per-storage-type capacityStandard, oversize, apparel, and dangerous goods each have their own limit, and the same SKU mix hits them differently.
  • Inbound in flightUnits in receiving still take cube. A spreadsheet that only looks at on-hand will overcommit you.
  • Capacity changes after IPI updatesAmazon resizes capacity when IPI moves. Your numbers from last month may not match this week's Capacity Monitor.
  • Mixed-SKU shipmentsCube-per-unit varies by SKU; planning a mixed PO needs a weighted average, not one input.
  • AWD & 3PL overflowSmart capacity planning means knowing what AWD and your 3PL can absorb, not just what FBA can take.
  • Sell-through changes per SKU'Fits' isn't the same as 'should send' — and per-SKU cover changes every week.
▲ Profit Hawk

Track FBA capacity continuously, per storage type.

Profit Hawk reads your real FBA capacity, inbound shipments, and AWD/3PL stock continuously — and alerts before a planned PO pushes you past your safe utilization line.

  • Per-storage-type capacity tracking
  • Inbound & on-hand cube combined
  • Overflow rebalance suggestions (AWD / 3PL)
  • Capacity-aware replenishment alerts
Start free trialSee Profit Hawk →
FAQ

FBA capacity, answered.

The questions Amazon sellers actually ask us about capacity, storage types, and how to plan inbound without blowing the limit.

Where do I find my actual FBA capacity limit?
In Seller Central, open Inventory → Capacity Monitor. Amazon measures storage capacity in cubic feet and assigns separate limits for each storage type (standard-size, oversize, apparel, dangerous goods). Your account-specific limit is the only one that matters — this tool deliberately doesn't guess.
Why does this tool ask me to enter my capacity instead of looking it up?
Because FBA capacity is per-account and per-storage-type, and the way Amazon allocates it changes. Professional sellers get capacity that varies with IPI and history, while individual accounts have a fixed cap. There's no public, current source that would be safe to bake in. Copying the number from your own Capacity Monitor is the only correct answer.
Should I include AWD or 3PL inventory in 'current FBA usage'?
No. This number is just what's physically inside Amazon's fulfillment centers and counted by Capacity Monitor. AWD and 3PL inventory have their own limits and economics. If you want to compare placement options, use the AWD vs FBA vs 3PL Storage Estimator.
What if I store multiple SKUs with very different sizes?
For the per-unit field, plug in the SKU you're actually about to ship. If you're planning a mixed shipment, either average the cubic-feet-per-unit weighted by units in the carton, or enter the total cubic feet of the proposed shipment divided by total units. The shipment-fit verdict only needs the aggregate footprint.
What's a healthy capacity utilization?
Most sellers should aim to stay under about 85% on each storage type. That headroom lets you cover demand spikes, accept inbound velocity slowdowns at FC receiving, and avoid forced removals. Running at 95%+ for long means one bad demand week can push you into capacity overages or trigger shipment restrictions.
Does this calculate the storage overage fee?
No — this tool checks whether the shipment physically fits within your current capacity limit. Storage overage fees and aged-inventory surcharges are separate calculations. Run the Aged Inventory Risk Calculator alongside this one to see slow-mover exposure.
What does 'days of cover after shipment' tell me?
It's a sanity check: even if a shipment fits in your capacity, it can still be too much. Days of cover translates total post-shipment units into how long they'll last at your current sales pace. If that number is past 180 days, you're shipping aged-inventory exposure into the future even though Amazon will accept it today.
Why did the verdict say 'fits, but tight'?
Because the shipment lands you at 90% or more of your capacity. It fits — but you've used up almost all the slack. One slow sales week, a delayed PO that comes in big, or a seasonal slowdown will push you into overage territory. Either send a smaller shipment or route the overflow to AWD or a 3PL.
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▲ Profit Hawk

Want capacity, inbound, and AWD/3PL tracked together?

Profit Hawk continuously reconciles your FBA capacity, inbound shipments, and overflow stock at AWD or your 3PL — and flags when a planned PO would push you past safe utilization.

Start free trialSee Profit Hawk