Start from an example:
Sales
units
units
Lead time
days
days
days
Days from delivery until units are sellable. Estimate; varies by season.days
days
Longer means fewer orders but more storage fees.Estimate. Use recent daily sales and add buffer before Q4 and Chinese New Year.
How the reorder point works
Reorder point
daily sales × (lead time + safety days)When stock on hand plus inbound falls to this number, place the next order.
Lead time
production + shipping + FBA check-inCount every day until units are live on Amazon, not just until they leave the factory.
Order quantity
daily sales × days each order coversBigger orders cut per-unit freight but raise storage fees and the risk of aged inventory.
Frequently asked questions
How much safety stock should I keep for FBA?
Two to three weeks of sales is a common starting point. Add more if your sales swing or your supplier is often late.
How long does FBA check-in take?
Often a few days to two weeks after delivery, and longer in Q4. Use your own recent shipments as the guide.
Why not just send a lot of stock at once?
Stock older than 180 days pays an aged inventory surcharge, and Q4 storage costs about 3× more. Smaller, regular orders keep fees down.