Reorder point calculator
Find the stock level at which you should raise a purchase order, so replenishment arrives before you run out. Enter average daily usage, supplier lead time and safety stock, and the calculator gives the reorder point and how many days of cover it represents.
The reorder point is the level at which you order, not the amount you order. Order quantity is a separate decision — see the economic order quantity calculator.
The reorder point is a level, not a quantity
The reorder point tells you when to order. It does not tell you how much to order — that is a separate decision, driven by order costs and holding costs.
The formula is demand during the lead time plus safety stock. If you use 40 units a day and your supplier takes ten days, you need 400 units just to survive the wait, plus whatever buffer you hold for the bad case.
Why this is where spreadsheets break
A reorder point is only useful if something checks stock against it continuously. In a spreadsheet, nothing does. Someone remembers to look, or they do not, and the first sign of a problem is a customer order that cannot be filled.
This is the most common reason Singapore SMEs move from spreadsheets to a stock system: not the reporting, but wanting the reorder alert to fire without anyone remembering to check.
Questions
How do I calculate a reorder point?
Multiply average daily usage by the supplier lead time in days, then add your safety stock. The result is the stock level at which you should place the next order.
Should the reorder point include safety stock?
Yes. Without it, you would be planning to hit exactly zero at the moment the delivery arrives, leaving no room for a late delivery or a busy week.
How often should I review reorder points?
At least twice a year, and immediately after any change of supplier or shift in demand. A reorder point set on last year's lead times quietly stops protecting you.
A calculator answers one question once. Digital 9 Labs builds the system that answers it continuously — your real numbers, updated as the work happens, without anyone reopening a spreadsheet.