Pull current sales velocity per SKU and your days of supply. Flag anything trending toward its reorder point before the next order would arrive.
2
Check what is already in transit
Subtract units already on a PO or inbound shipment so you do not double-order. Reserved and in-transit units are not sellable cover yet.
3
Trigger the SKUs at or below reorder point
For each SKU at or below its reorder point, size the order to cover demand to the next cycle plus safety stock, respecting MOQ and cash.
4
Frequently Asked Questions
How do I know when to reorder on Amazon FBA?
Reorder when your available inventory drops to the reorder point, which is your daily sales velocity multiplied by your total lead time, plus your safety stock. Because FBA lead times are long, that trigger often fires while you still appear to have plenty of stock.
How much inventory should I reorder?
Order enough to cover demand until your next planned order arrives, plus your safety buffer, while respecting your supplier's minimum order quantity and the cash you have on hand. The economic order quantity formula balances ordering cost against holding cost to find an efficient size.
Why is restock planning harder on Amazon than in a normal store?
Andrew Erickson is the founder of Inventory Hero. He has spent years working with Amazon FBA sellers on demand forecasting, restock planning, and the cash flow side of running a private-label brand. Inventory Hero exists because every spreadsheet-based inventory system he tried eventually broke — usually right before Q4.
Work backward from the peak or the stockout date through the full lead time so the PO goes out early enough to land before you run dry.
Three reasons: lead times are long and multi-leg, so you commit cash months ahead of demand; Amazon caps how much you can send in through restock and capacity limits; and storage surcharges punish anything that moves slowly. All three reward planning per SKU instead of a flat rule.
Read article
Amazon FBA restock planning is the system you use to decide, for every SKU, when to place a purchase order and how much to order, so you stay in stock without burying cash in inventory that sits. The short version: reorder when available stock hits your reorder point (daily sales velocity times your total lead time, plus safety stock), and size each order to cover demand to your next cycle plus a buffer. Below is the full system, the formulas with worked numbers, and the FBA-specific constraints that quietly wreck a restock plan built for a normal store.
Amazon FBA restock planning is the ongoing process of forecasting each product's demand and timing your purchase orders so inventory arrives before you run out, without ordering so much that cash and storage costs pile up. It runs per SKU, on that SKU's real sales velocity and real lead time, not on a single rule applied to the whole catalog.
The reason it deserves its own system on Amazon is that the platform punishes both mistakes. Run out and you lose the sale and the ranking that came with it, with no backorder to soften the blow. Overbuy and you pay storage month after month, drag your
IPI (Inventory Performance Index)
Amazon's 0 to 1,000 score for how efficiently you manage FBA inventory, which governs your storage limits.
down, and eventually eat aged-inventory surcharges. Restock planning is how you stay in the narrow band between those two.
You reorder when available inventory drops to your reorder point. The formula is:
Reorder point = (daily sales velocity x total lead time in days) + safety stock
The first part is the stock you will sell while you wait for the order to arrive. The second part is the cushion for the days demand runs hot or the shipment runs late. When on-hand inventory reaches that number, the PO goes out, even if the shelf still looks comfortable.
Say a SKU sells 12 units a day, your total lead time is 60 days, and you carry 120 units of safety stock:
Input
Value
Daily sales velocity
12 units
Total lead time
60 days
Safety stock
120 units
Reorder point = (12 x 60) + 120 = 840 units. The moment available inventory hits 840, you order, even though 840 units feels like a lot of stock on hand. That is the part new sellers get wrong: on a 60-day lead time, "plenty of stock" is exactly when you need to be placing the order. Run your own numbers in the free reorder point calculator, and for the deeper treatment see when to reorder: the signals sellers miss.
Once the reorder point tells you when, the order quantity tells you how much. At a minimum, order enough to cover demand until your next planned order arrives, plus safety stock, while respecting your supplier's minimum order quantity and the cash you have available.
The more precise answer is the economic order quantity, which balances the cost of placing an order against the cost of holding inventory. Order in big batches and you place fewer orders but carry more
Cycle Stock
the working inventory you expect to sell between replenishments, separate from safety stock.
Most weeks the binding constraint is not demand, it is cash: ten SKUs hit their reorder point and you can only fund six purchase orders. The wrong move is first-come-first-served, or reordering whatever simply looks lowest. Prioritize by the cost of being wrong:
Stockout cost first. A fast, high-margin SKU about to run dry loses you the most for every day it is out of stock, including the ranking you then have to rebuild. Fund these before anything else.
Then cash velocity. Between two SKUs at similar stockout risk, favor the one that returns cash faster (higher margin, faster sell-through). That cash funds the next round of orders sooner.
Defer the slow and the safe. A SKU with months of cover, or a slow mover you are winding down, can wait. Reordering it now just freezes cash you need elsewhere.
Respect the hard floors last. MOQ and any inbound or capacity limit can push an order up or cap it; work those in after you have ranked, not before.
The point is that restock planning is a portfolio decision, not ten independent ones. When cash is the limit, the question is not "which SKUs are low" but "which dollars protect the most profit."
The lead time that matters is not the production time your supplier quotes. It is the full chain: raw-material sourcing, production, ocean freight, customs, and Amazon check-in, which can add its own variable delay before units become sellable. Plan total lead time in weeks or months and build it into the reorder point, or your trigger fires too late every time. See what lead time really is on FBA.
Restock and capacity limits put a ceiling on how many units you can have in the network, regardless of demand. A tight limit can block your best sellers while slow movers eat the space, which is why your IPI and your restock limits are part of the plan, not separate from it.
Monthly storage fees, and the aged-inventory surcharge on units that linger, mean overstock is not free insurance.1 Every extra unit of a slow mover is rent you pay until it sells. That is why restock planning is about the right amount, not the most you can fit. For the demand-side risk on the other end, see Amazon FBA stockout prevention, and if you hold buffer stock upstream, AWD vs FBA covers where to keep it.
Restock planning is a weekly habit, not a quarterly project. The loop is short:
Update velocity and days of cover. Pull current sales velocity and days of supply per SKU, and flag anything trending toward its reorder point before the next order would land.
Check what is already in transit. Subtract units already on a PO or inbound shipment so you do not double-order.
Trigger the SKUs at or below reorder point. Size each order to cover demand to the next cycle plus safety stock, within MOQ and cash.
Place POs against backward-planned dates. Work backward through the full lead time so the order goes out early enough to land before you run dry.
Every number above starts from data you already have:
Sales velocity comes from your units-sold history. In Seller Central, the Business Reports (by ASIN, over a date range) give you units ordered per day. Exclude any days the SKU was out of stock, or the velocity reads artificially low and your reorder point comes out too small.
On-hand and days of supply come from the FBA inventory dashboard, but plan on sellable units, not total, since reserved and in-transit stock cannot fill an order today.
Lead time comes from your own purchase-order records: the full chain from order placed to units sellable, not the supplier's quoted production time.
Demand variability is the spread in that same daily sales history, a spreadsheet standard deviation over the last 30 to 60 days.
The friction is real: pulling all of this per SKU, every week, by hand is a meaningful time cost once you pass a few dozen SKUs, which is exactly the work a planning tool should take off your plate.
Using one weeks-of-cover rule for the whole catalog. It overstocks steady sellers and starves spiky ones. Plan per SKU. The right thresholds live in your min and max inventory levels.
Planning on quoted production time, not total lead time. The freight, customs, and check-in legs are where stockouts hide.
Treating reserved and in-transit units as available cover. They are real inventory, but they cannot fill an order today.
Reordering only when the shelf looks low. On a long lead time, that is already too late.
Amazon FBA restock planning comes down to two numbers per SKU, calculated on real velocity and real lead time: the reorder point that tells you when to order, and the order quantity that tells you how much. Build those from the four inputs above, respect the FBA constraints that make the platform unforgiving, and run the weekly loop. That is the difference between a catalog that funds its own growth and one that lurches between stockouts and dead stock.