Calculate a reorder point for a paper SKU
The reorder point is the inventory level at which you should consider placing an order. Estimate the stock you expect to use while waiting for a delivery and add enough safety stock to absorb ordinary variation. This calculator uses average sheets used per day multiplied by lead time, plus average use multiplied by the number of buffer days you choose. It rounds the trigger up to the next whole sheet.
A trigger is most useful when it is compared with inventory position. Inventory position is usable stock on hand plus confirmed incoming stock minus sheets already reserved for jobs. Compare this position with the trigger so you can account for commitments and deliveries before ordering another case. Use a separate line or calculation for every paper size, finish, and weight that you manage as a distinct item.
Worked example for 120 sheets per day
A shop uses an average of 120 sheets daily and normally receives this stock four days after ordering. Expected use during lead time is 480 sheets. Adding two buffer days adds 240 sheets, making the reorder point 720. The shop counts 540 usable sheets, expects 100 confirmed incoming sheets, and has 80 already reserved. Its inventory position is 560 sheets, so it is below the reorder point.
| Lead time | Buffer | Reorder point |
|---|---|---|
| 3 days | 2 days | 600 sheets |
| 4 days | 2 days | 720 sheets |
| 6 days | 2 days | 960 sheets |
Choose inputs that reflect your shop
Start with recent usage for the same stock. Count sheets issued to jobs and include normal setup and spoilage. Divide by the number of days on the same basis used for lead time. If your shop operates five days per week and the supplier states business days, using shop days is often simpler. When deliveries or usage continue on weekends, consider a calendar-day basis instead and use it for all inputs.
Review lead time from actual received orders, including order cutoffs and any time required to check or move material into usable stock. A supplier’s dispatch promise tells you when parcels leave its site. The lead time you need ends when your press operator can use the stock. Add a buffer suitable for delays you have seen and the cost of stopping a job or switching materials.
Common inventory mistakes
An open purchase order can raise inventory position while the floor still lacks enough paper for tomorrow’s job. When an incoming delivery arrives later than the planned run, review that date separately. Reconcile reserves after a job ships or is cancelled, and remove damaged stock before counting on-hand inventory. If your business has a seasonal spike, run a second calculation using the expected peak-day rate. Keep case sizes and storage limits in mind when deciding how much to buy.
Frequently asked questions
Does the reorder point tell me how many sheets to buy?
It tells you when the stock reaches the trigger. Choose the order quantity based on the next jobs, case sizes, cash, and storage space.
Should I include material held for existing orders?
Count it in usable stock only if it is physically available, then subtract the reserved quantity to avoid offering those sheets to other jobs.
How often should I update daily usage?
Recheck when your work mix, season, or paper specifications change. A stock item newly added to your shop may need a provisional rate until enough jobs are recorded.
What if I only buy special paper per job?
Plan individual orders around approved jobs and their delivery deadlines. A stock trigger is most useful for items you intend to keep on hand.