Operator guide
Amazon FBA Reorder Point: How to Calculate It (2026)
Your reorder point is the on-hand inventory level that should trigger a new purchase order. Get it wrong on the low side and you stock out, lose rank, and hand sales to a competitor. Get it wrong on the high side and you pay Amazon to store dead units. Here is the formula, a worked example, and the part most guides skip: what 2026 lead times and fees actually do to the math.
The short answer
Reorder point equals (average daily units sold times total lead time in days) plus safety stock. For Amazon FBA, total lead time is not just your supplier quote. It is supplier production plus freight transit plus Amazon receiving and check-in time. When your sellable inventory drops to that number, you place the next order.
Formula
Reorder point = (average daily sales x total lead time in days) + safety stock
Total lead time = supplier production days + freight transit days + Amazon receive and check-in days
Worked example
Say a SKU sells 40 units a day on a steady trend. Your supplier needs 30 days to produce. Ocean freight plus drayage runs 35 days door to Amazon. Amazon then takes another 14 days on average to receive, scan, and make the shipment sellable. Total lead time is 79 days, not the 30 your supplier quoted.
- Lead-time demand: 40 units x 79 days = 3,160 units
- Safety stock (covering, say, 20 days of demand variability): 40 x 20 = 800 units
- Reorder point: 3,160 + 800 = 3,960 units
The moment sellable inventory hits 3,960 units, the PO goes out. A seller who used the 30-day supplier number alone would set a reorder point near 1,200 units and run out roughly seven weeks before the next shipment cleared. That is the exact mistake that tanks a launch before Q4. For how to size the 800-unit buffer properly, see the safety stock guide.
The 2026 lead-time and fee reality
Most reorder-point content still treats lead time as the factory number and ignores what Amazon changed. Three 2026 facts move the math:
Amazon receiving time is part of lead time
Inventory in transit or sitting in the receive queue is not sellable and does not protect your rank. Measure your real check-in time from recent shipments and add it to every reorder calculation. It is routinely one to three weeks and it is the single most underestimated input.
The low-inventory-level fee sets a floor
Amazon assesses a low-inventory-level fee when both your short-term (past 30 days) and long-term (past 90 days) historical days of supply fall below 28 days, evaluated per FNSKU rather than per parent ASIN. Practically, your reorder point and safety stock should keep on-hand plus inbound above roughly 28 days of supply so a normal cycle does not trip an extra per-unit fee. Confirm the current rate in your Seller Central fee schedule, as Amazon adjusts it.
Capacity is capped at about five months of sales
FBA capacity limits are now tied to roughly five months of forecasted sales. Ordering far past your reorder point to feel safe can push you into restock limits or the aged-inventory surcharge instead. The reorder point is a trigger to act, not a license to overstock. See the 2026 aged-inventory surcharge guide for the cost of holding too long.
Frequently asked questions
What is the reorder point formula for Amazon FBA?
Reorder point equals (average daily units sold times total lead time in days) plus safety stock. Total lead time for FBA is supplier production plus freight plus Amazon receiving and check-in time, which in 2026 commonly runs longer than the supplier quote alone.
Does the reorder point include Amazon receiving time?
Yes. The reorder point has to cover the full pipeline, not just the factory. For FBA that means supplier lead time plus freight transit plus the days Amazon takes to receive, scan, and make a shipment sellable. Treating the supplier quote as your only lead time is the most common reason sellers stock out.
How does the 2026 fee regime change the reorder point?
Amazon now charges a low-inventory-level fee when both your 30-day and 90-day historical days of supply sit below 28 days, evaluated at the individual FNSKU level. That sets a practical floor: your reorder point and safety stock should keep on-hand plus inbound above roughly 28 days of supply so a normal reorder cycle does not trip the fee.
How often should I recalculate my reorder point?
Recalculate whenever sales velocity shifts, ahead of a known seasonal peak, and any time a supplier or freight lane changes lead time. Velocity and lead time are the two inputs that move, so a reorder point set once and never revisited is the one that fails before Q4.
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