Product reorder calculator
When to reorder a product and how much, so the shelf isn’t empty while the next batch is on its way: reorder point, safety stock and the date the product runs out. With the supplier’s lead time and pack size.
Free, no sign-up. Everything is calculated in your browser, no data is sent anywhere.
Sales and stock
On its way from the supplier, not in stock yet
From placing the order to goods on the shelf
For a late delivery or a spike in sales
How many days of sales one batch should last
The supplier sells in packs of this many
Optional: we’ll show the order total
What to do
Order today: stock is already at the reorder point.
- Sales per day
- 3.57 pcs
- Runs outIf nothing is reordered
- in 16 days
- Order
- today
- Safety stock
- 18 pcs
- Order
- 115 pcs
How it’s calculated
Reorder point
The stock level that lasts exactly the lead time plus the safety stock. Once you hit it, it’s time to order — otherwise the shelf empties before the goods arrive.
Safety stock
The supplier is late or sales jump — a few days of stock save you from «out of stock». The less predictable the delivery, the more days to plan for.
Packs and money
If the supplier sells in packs, the calculator rounds the quantity up to whole packs. Add the purchase price to see how much money goes into the batch.
Questions
FAQ
What is a reorder point?
The stock level at which it’s time to place a new order: sales per day × (lead time + safety stock days). For example, 4 pcs a day, 14-day delivery and 5 days of safety stock — order when 76 pcs are left.
How many days of safety stock do I need?
It depends on how predictable your deliveries and sales are. If a product often runs out before the batch arrives, increase it; if it sits for months, reduce it. Imports that can be held at customs usually need a bigger buffer.
What counts as lead time?
All the time from deciding to order to goods ready for sale: payment, the supplier packing the order, delivery and receiving. Not just the parcel’s journey.
What if my sales are seasonal?
Enter last week’s sales or the sales you expect next month, not the yearly average. Order with a bigger buffer before the season.
How do I do this for a hundred products?
By hand it takes ages. In Рекс the «Inventory» report counts days of stock for every product from the last 30 days of sales and lists the ones that will run out soon.
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Рекс sees what’s running out on its own
The «Inventory» report counts days of stock for every product from the last 30 days of sales and lists the ones that will run out soon. Purchases in transit are shown next to them.
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