Finished product
Schedule a finished-product batch
At 2 products per day, 3 production days, 4 products of safety stock, and a 10-day target, the low-stock point is 10 and target stock is 24. With 8 on hand, schedule 16 more.
Filament and Maker Inventory Reorder Calculator
Enter recent daily use, supplier or production lead time, safety stock, and the coverage you want after replenishing. The calculator returns a low-stock point and a target quantity for that item.
Set one inventory threshold
Free to use in this browser. Nothing is saved unless you choose to continue in PlyOps.
Inputs
Set the low-stock point
The threshold should cover normal use while a replacement batch or supplier order is still on the way.
each
each / day
days
each
days
Reorder point = use during lead time + safety stock
This is a planning trigger, not a purchase order or automatic production instruction.
Modular organizer
Stock is above the trigger
18 each on hand is above the 15 each low-stock point.
- Low-stock point
- 15 each9.8 each expected while replenishment is pending.
- Target stock
- 35 each21 days of use plus the entered safety stock.
- Days on hand
- 12.9 daysEstimated from 1.4 each per day.
- Batch quantity
- 0 eachNo replenishment needed at the current target.
Input check
A daily-use estimate is included.
Lead time is included.
Safety stock is included.
Current stock covers expected lead-time use.
Revisit the inputs after a demand shift, supplier change, seasonal event, or meaningful change in production capacity.
Save this stock threshold to an item
Choose a saved finished product, then review a low-stock point of 15 each and target stock of 35 each. Current quantity is never changed.
This result is available in this tab for up to two hours. Nothing is saved until you review and confirm it. How result handoff works.
See the reorder formulas, examples, and limitsOpen the detailed reference when you want to check how the result is calculated or where the tool stops.
Turn recent use into one stock threshold
This calculator estimates when one item may run low. It does not initiate purchasing, schedule production, reserve stock for open sales, or change a marketplace quantity.
Method last checked .
Method
1. Choose one stock item
Calculate a separate threshold for each finished product, material, hardware part, or outer shipping package that has its own on-hand quantity.
2. Use a representative daily average
Base daily use on a recent period that matches the season and workload you are planning for. Keep the unit consistent throughout the calculation.
3. Enter the full lead time
For a finished product, include printing and finishing time. For a shop supply, include the time from placing an order until the item is usable.
4. Choose safety stock
Add a buffer for demand spikes, failed prints, supplier delays, or other variation that the daily average does not capture.
5. Set target coverage
Choose how many days the replenished stock should cover before touching the safety buffer.
6. Review after conditions change
Recalculate after a supplier, production rate, season, product mix, or sales pattern changes enough to make the old inputs unrepresentative.
Formulas used by the calculator
- Low-stock point
- ceil(average daily use × lead-time days + safety stock)
- Target stock
- ceil(average daily use × target-coverage days + safety stock)
- Replenishment quantity
- max(0, target stock − floor(on hand)), only when on hand is at or below the low-stock point
- Estimated days on hand
- on hand ÷ average daily use
Four item-specific examples
Filament or material
Restock material
At 180 g per day, 5 delivery days, 500 g of safety stock, and a 14-day target, the low-stock point is 1,400 g and target stock is 3,020 g. With 1,200 g on hand, restock 1,820 g.
Purchased hardware
Restock hardware
At 12 screws per day, 7 delivery days, 50 screws of safety stock, and a 21-day target, the low-stock point is 134 and target stock is 302. With 100 on hand, restock 202 screws.
Shipping box or mailer
Restock outer shipping packages
At 6 boxes per day, 10 delivery days, 24 boxes of safety stock, and a 30-day target, the low-stock point is 84 and target stock is 204. With 70 on hand, restock 134 boxes.
Assumptions and limits
- The calculation assumes the entered daily average and lead time are useful planning estimates, not guaranteed future values.
- On-order supplies, work in progress, reserved stock, minimum order quantities, case packs, and supplier price breaks are not included.
- All values must use the same unit for one item: products, grams, screws, boxes, or another unit chosen by the seller.
- Safety stock carries the uncertainty. A volatile item may need a larger buffer or a separate seasonal calculation.
- The on-hand value can cover several locations only when the user intends to plan those locations as one pool.
- For packaging, use a real outer shipping package such as a box or carrier-ready mailer. Padding and inserts are separate supplies.
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