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Reorder point calculator

The reorder point is the inventory level at which you place a new order: demand during the supplier lead time plus safety stock.

units/day
days

Days from order to stock ready to sell.

units

Use the safety stock calculator if you are not sure.

units

Optional. Used to say whether to order today.

units
Reorder point
565 units

Order when your inventory position falls to this level.

Demand during lead time
420 units
Inventory position now
400 units

On hand plus on order.

Order today?
Yes, at or below the reorder point

Working

  1. Demand during lead time: 20 × 21 = 420 units
  2. Reorder point: 420 + 145 safety stock = 565 units
  3. Inventory position: 400 on hand + 0 on order = 400 units

Runs in your browser; nothing you enter is sent anywhere. Results are estimates from the numbers you provide.

The formula

Reorder point = (average daily demand × lead time) + safety stock

How it works

While you wait for a purchase order to arrive you keep selling. The reorder point is set so that the stock still on the shelf when the order lands is your safety stock, not zero.

Compare it with your inventory position, which is on hand plus on order minus anything committed. Comparing against on-hand alone makes you order again for stock that is already on its way.

A reorder point is a trigger, not an order quantity. How much to order depends on cost, minimum order quantities and cash; see the EOQ calculator.

Worked example

A product sells 20 units a day and the lead time is 21 days, so lead-time demand is 420 units. With 145 units of safety stock the reorder point is 565. If you have 400 on hand and nothing on order, you are below the reorder point and should order now.

Watch out for

  • Using a fixed reorder point all year ignores seasonality. A point set in March is too low for November.
  • Use the realistic lead time, including time to receive and put away, not the supplier's quoted production time.
  • If an order is already on the way, include it in your inventory position or you will double-order.

Frequently asked questions

What is the difference between reorder point and safety stock?
Safety stock is the buffer. The reorder point is the trigger level, which is the buffer plus the demand you expect while waiting for the order to arrive.
Should the reorder point change through the year?
Yes for seasonal products. Because demand during lead time changes, the reorder point should too. Stokrio recalculates it from the forecast rather than keeping a static number.
Do I include stock on order in the comparison?
Yes. Compare the reorder point with inventory position (on hand plus on order, less committed), not just on-hand.

Shopify App · 3PL Partner API · US$39/mo entry plan

Skip the spreadsheet

Stokrio runs these calculations for every product, using your own sales and supplier lead times.

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