Reorder Point vs. Reorder Quantity

"Reorder point" and "reorder quantity" get used interchangeably often enough that people assume they're two names for one number. They're not. A store can have a perfectly good reorder point while still guessing at the quantity, or the other way around: getting one right doesn't automatically get you the other.

The two definitions

• Reorder point: the stock level that tells you when to place an order. Covered in full, with the formula and a worked example, in the reorder point formula guide.
• Reorder quantity: how many units to order once you've hit that point. Covered in full in reorder quantity: how much stock to order.

Neither formula is repeated here — both posts already own their number. What's useful in one place is putting the two side by side on the same SKU, so the distinction is concrete rather than just definitional.

Why they get confused

Both draw on the same three ingredients: sales velocity, lead time, and a safety buffer. That overlap is exactly why the two numbers blur together in conversation — "what's our reorder number for this SKU?" could mean either one, and the two tend to go wrong together, since a bad velocity estimate breaks both calculations at once.

The difference is what each one covers. The reorder point looks only as far as the next delivery: lead-time demand plus a buffer. Reorder quantity looks further, out to the target stock level covering the full stretch until the next planned order, then subtracts what's already on hand and on order. One is a trigger; the other is a fill-up amount.

Side by side, on one SKU

"Cedar & Fig, 250g" sells 5 units a day, with a 12-day lead time and 30 units of safety stock.

At 90 units left, it's time to order. The order itself is sized to bring the shelf back up to a 240-unit target stock level, which at that moment means ordering 150 units. Same SKU, same underlying sales data, two different numbers because they're answering two different questions: one about timing, one about size.

Both numbers are pieces of a larger process. See the Shopify inventory replenishment guide for how reorder point, reorder quantity, cadence, and prioritization fit together.

Frequently Asked Questions

What's the difference between a reorder point and a reorder quantity?

The reorder point is a trigger: the stock level at which you place an order. The reorder quantity is the size of that order: how many units to buy. One tells you when; the other tells you how much.

Do you need both numbers?

Yes. A reorder point without a reorder quantity tells you it's time to act but not what to type into the purchase order. A reorder quantity without a reorder point tells you how much to buy but not when, and you'd be guessing at timing, which is the more expensive mistake of the two.

Which one do you calculate first?

The reorder point. It sets the trigger that starts the whole reorder process; the reorder quantity is calculated at the moment that trigger fires, using whatever stock is on hand and on order at that time.

Recalculating both by hand, per SKU, every cycle, is the part that quietly stops happening as a catalog grows. StockCue computes the reorder point on every plan including Free, and sizes the order to match once you're on Starter and up.