Reorder Point Calculator
Determine the optimal time to reorder inventory and prevent stockouts
Average number of units sold or used per day
Time from placing order to receiving inventory
Extra buffer stock to prevent stockouts
A reorder point is the inventory level at which you should place a new order to replenish stock before it runs out. It accounts for the time it takes to receive new inventory (lead time) and includes a safety stock buffer to prevent stockouts due to unexpected demand or supply delays.
Reorder Point = (Lead Time × Daily Usage Rate) + Safety Stock
Components:
- •Average Daily Usage: Units sold/used per day
- •Lead Time: Days to receive new inventory
- •Safety Stock: Buffer for unexpected demand
Our platform automatically:
- ✓Calculates reorder points based on sales history
- ✓Alerts you when stock reaches reorder level
- ✓Adjusts for seasonal demand patterns
- ✓Generates purchase orders automatically
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What next?
Store this threshold once per product and let Ordavia warn you before a stockout, instead of recalculating it every month.
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See also
Updated on 9 October 2026
How to use the reorder point calculator
The reorder point is the stock level that should trigger a new purchase order. Order at that level and the delivery arrives just as you reach your safety stock.
- Work out your daily usage rate: units sold over a period, divided by the number of days in that period.
- Enter the lead time in days, from the moment you place the order to the moment the goods are on your shelf. Include the supplier's processing time, transit and your own receiving.
- Enter your safety stock, the buffer you keep for demand peaks and late deliveries. Leave it at zero if you do not keep one.
- Click calculate. Reorder as soon as stock on hand plus stock already on order falls to the reorder point.
Worked example
A wholesaler sells 40 cartons a day. The supplier delivers in 7 days. Safety stock is 100 cartons.
Reorder point = (7 × 40) + 100 = 380 cartons.
When stock reaches 380 cartons, a new order goes out. Seven days later about 280 cartons have been sold, and the delivery arrives with roughly 100 cartons left.
A simple way to size the safety stock
| Step | Example |
|---|---|
| Highest daily usage × longest lead time | 55 × 10 = 550 |
| Average daily usage × average lead time | 40 × 7 = 280 |
| Safety stock = the difference | 550 − 280 = 270 |
Common mistakes
- Mixing calendar days and working days. Use the same unit for usage and for lead time.
- Ignoring stock already on order, which leads to ordering twice.
- Using a yearly average for a seasonal product. Recalculate before each peak season.
- Keeping an old lead time after changing supplier or shipping route.
Frequently asked questions
What is the difference between the reorder point and the reorder quantity?
The reorder point tells you when to order. The reorder quantity tells you how much. They are calculated separately: the quantity depends on ordering costs, storage costs and supplier minimums.
How often should I recalculate the reorder point?
Whenever demand or lead time changes noticeably, and before each seasonal peak. A reorder point set once and never reviewed slowly drifts away from reality.
Can safety stock be zero?
Yes, if demand and lead time are both very stable and a short stockout costs little. For anything a customer would buy elsewhere the same day, keep a buffer.
Does the formula work for products with irregular sales?
It works best for products that sell steadily. For items that sell rarely or in bursts, review each order by hand or keep a fixed minimum quantity instead.