Reorder Point Calculator

Running out of stock on a product that's selling is the fastest way to hand your rank to a competitor. You were eight days from a shipment, sales kept climbing, and suddenly the buy box went quiet. Reorder point is the one number that stops that — it tells you how many units should be left when you pull the trigger on the next purchase order.

The math is dull on purpose: average daily sales times lead time, plus safety stock. The lead time is the full run from "I clicked reorder" to "units are sellable in the warehouse" — supplier build, ocean or air, customs, inbound, and Amazon's receiving, which lately can sit for weeks. A lot of sellers count only the transit and wonder why they still stocked out.

Safety stock is your cushion for the bad week. If a product normally moves 20 a day but spiked to 50 during a promo, that gap is what eats you. Put a realistic number there, not zero.

Watch the 200-unit shipment cap Amazon pushed on some inbound plans. If your reorder point says send 600 units but your plan only accepts 200 per shipment, you're making three shipments and eating placement fees three times. The Shipment Unit Planner on this site handles that math.

Set the reorder point, then wire it into a calendar reminder. The point isn't to admire the number — it's to start the PO before you hit it. Most stockouts I've seen weren't surprises. They were "I meant to reorder" that slipped two weeks, right into a stockout.