Reorder point, safety stock, and stockout cost calculator
Enter your demand and lead time to get the three numbers every inventory plan needs, with the formulas shown so you can see exactly how they are worked out. Free, no signup, and accurate to the standard formulas.
By Niyu Labs · works for any inventory, with Odoo-specific notes below
Reorder point
640units
40 x 14 + 80 = 640
Estimates for planning. Demand, lead time, and variability change over time, which is exactly what a forecast keeps up with.
Niyu Smart Stock computes the reorder point, safety stock, and the buy or transfer for every product and warehouse in Odoo, recomputed daily from a demand forecast. This calculator does one line at a time.
See it on the free tierWhat the reorder point tells you
The reorder point is the on-hand level that should trigger a new order. Hit it, and you place the order so the stock lands just as you would otherwise run out. Set it too low and you stock out during the lead time; too high and you tie up cash early.
Reorder point = average daily demand x lead time (days) + safety stock
Example: 40 units/day x 14 days + 80 safety = 640 units
Why safety stock is more than a guess
Safety stock is the buffer that absorbs demand that runs hotter than average and suppliers that run late. A service level turns a target like 95% into a number using how much your demand actually varies, which is sharper than holding a flat number of days for every product.
Safety stock = Z x daily demand std dev x sqrt(lead time)
Example at 95% (Z = 1.65): 1.65 x 12 x sqrt(14) = 74 units
Service level to Z
90% = 1.28, 95% = 1.65, 97% = 1.88, 98% = 2.05, 99% = 2.33. A higher service level holds more stock to miss fewer sales. The right level depends on the margin you make and the cost of a stockout, which the third tab helps you weigh.
What running out actually costs
The clearest cost of a stockout is the gross margin on the sales you miss while the shelf is empty. The estimate below is a floor, because it leaves out the customer who does not come back and the rush freight you pay to recover.
Lost margin per year = average daily demand x gross margin per unit x stockout days per year
Example: 40 units/day x 8 margin x 12 days = 3,840 per year, for one product
In Odoo, this runs by itself
Doing this by hand for one product is useful. Doing it for thousands, every day, as demand shifts, is what breaks. Niyu Smart Stock computes the reorder point, safety stock, and the buy or transfer for every product and warehouse inside Odoo, from a demand forecast that updates daily.
Frequently asked questions
How do you calculate a reorder point?+
The reorder point is the stock level at which you place a new order so it arrives before you run out. The formula is average daily demand multiplied by the lead time in days, plus your safety stock. For example, 40 units a day over a 14-day lead time, with 80 units of safety stock, gives a reorder point of 640 units.
How is safety stock calculated?+
Two ways. The service-level method is Z multiplied by the standard deviation of daily demand multiplied by the square root of the lead time, where Z comes from your target service level (95% is about 1.65). The simpler method is average daily demand multiplied by the number of safety days you want to hold. The calculator does both.
What does a stockout actually cost?+
At minimum it costs the gross margin on the sales you miss while the product is unavailable. The estimator multiplies average daily demand by the gross margin per unit by the number of days you expect to be out of stock in a year. It does not count the harder costs like lost customers and expedited freight, so treat it as a floor.
Is this calculator free?+
Yes, it is free and needs no signup. The result shows on the page. You can optionally enter an email to receive your numbers and an Odoo inventory-planning checklist.
How does Niyu Smart Stock do this in Odoo?+
Niyu Smart Stock computes the reorder point, safety stock, and the resulting buy or transfer for every product and warehouse inside Odoo, recomputed daily from a demand forecast rather than a static number you maintain. This calculator works one line at a time; Smart Stock does the whole catalog.
Skip the spreadsheet. Plan in Odoo.
Niyu Smart Stock turns these formulas into a daily plan for your whole catalog, with the buy and transfer drafted for approval. Start on the free tier.