What is a reorder point?

The inventory level at which you place a new order — Lead Time Demand plus Safety Stock — so replacement stock arrives just as you're running low.

How much safety stock should I hold?

For most small sellers, 14–30 buffer days of average daily sales is enough. Higher-volume or more variable products benefit from the max-demand/max-lead-time method.

How many days of supply should each order cover?

60–120 days is typical. Fewer days = more flexibility and less cash tied up; more days = lower freight and admin cost per unit and better volume discounts.

How do I avoid Amazon's aged-inventory surcharges?

Forecast realistically, order conservatively, and remove or liquidate stock before it crosses 181 days. Don't ship Q4 inventory months in advance — peak storage rates punish it.

Amazon FBA Inventory Management Guide

Inventory sits on a knife's edge between two expensive failures. Stockouts crush ranking and revenue; overstock locks up cash and racks up storage fees. This guide gives you the system — forecasting, lead times, reorder points, safety stock — to keep the right amount of stock in the right place at the right time.

Why inventory management matters

Inventory directly drives ranking, cash flow, fee exposure, and your ability to scale. Stockouts cost ranking that takes weeks of ad spend to win back; overstock freezes cash and triggers aged-inventory surcharges. For a physical-products seller, inventory management largely is the business.

Lead time: the foundation

Lead time = supplier production + transit + customs + Amazon check-in. Typical overseas private-label lead times run 45–90 days. Always plan for the realistic worst case, not the average — a supplier who normally ships in 25 days might take 40 in peak season.

Forecasting demand

Start with daily sales velocity from a recent representative window (7/30/90 days). Adjust for trend (growing or shrinking), seasonality, and planned promotions or ad pushes. Practical formula: Forecast = Base Velocity × Period Days × Trend Factor × Seasonal Factor. Refine monthly.

Reorder points and safety stock

Lead Time Demand = Avg Daily Sales × Lead Time. Safety Stock buffers variability: simple method = Avg Daily Sales × 14–30 buffer days; variability method = (Max Daily Sales × Max Lead Time) − (Avg × Avg). Reorder Point = Lead Time Demand + Safety Stock — reorder the moment sellable + inbound stock drops to that level.

How much to order

Order Quantity = Avg Daily Sales × Target Days of Supply. Most sellers target 60–120 days per order. Faster-growing sellers order smaller and more often to stay flexible; established sellers order larger batches to capture volume discounts when holding cost permits.

Storage fees shape your decisions

Q4 storage rates (Oct–Dec) are roughly 3× the rest of the year. Aged-inventory surcharges start at 181 days. Plan arrivals to sell through quickly rather than sit through the expensive months — and remove or liquidate dead stock before it crosses 365 days.

Common mistakes

Underestimating lead times, ignoring lead-time variability, no safety stock, ordering Q4 inventory too early, treating inventory as a back-office chore, and over-ordering before a product is validated. Fix these and most stockouts and overstocks disappear.

Frequently asked questions

What is a reorder point?: The inventory level at which you place a new order — Lead Time Demand plus Safety Stock — so replacement stock arrives just as you're running low.
How much safety stock should I hold?: For most small sellers, 14–30 buffer days of average daily sales is enough. Higher-volume or more variable products benefit from the max-demand/max-lead-time method.
How many days of supply should each order cover?: 60–120 days is typical. Fewer days = more flexibility and less cash tied up; more days = lower freight and admin cost per unit and better volume discounts.
How do I avoid Amazon's aged-inventory surcharges?: Forecast realistically, order conservatively, and remove or liquidate stock before it crosses 181 days. Don't ship Q4 inventory months in advance — peak storage rates punish it.

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