Makeratory Resources / Guides
Filament inventory guide
How to track your 3D printer filament inventory
A reliable filament inventory tells you what material and colors you have, where each spool is stored, and whether enough remains for the next print.
What should you track?
A useful filament inventory does not need dozens of fields. Start with the information that helps you answer real questions before a print or purchase.
- Brand and material — for example, SUNLU PETG or Bambu Lab PLA Basic.
- Color — ideally using the manufacturer's color name when you may need to reorder it.
- Spool size — usually 1 kg, but not always.
- Quantity or estimated amount remaining — unopened, full, partial, or a measured gram estimate.
- Storage location — shelf, dry box, AMS, dryer, cabinet, or another useful location.
- Purchase cost — useful when you want to understand material cost later.
Optional details such as nozzle compatibility, drying history, lot number, vendor, and purchase date can be useful, but collecting information you never use makes an inventory harder to maintain.
Three practical ways to track filament
1. Visual inventory
For a small collection, organized shelves and clear bins may be enough. Grouping by material and color makes it easy to see what is available. The weakness is partial spools: a spool on the shelf tells you that you own the color, not whether it contains enough filament for a 350 g print.
2. Spreadsheet
A spreadsheet is a strong next step because it is inexpensive, flexible, and easy to customize. One row per spool can track brand, material, color, starting weight, remaining weight, location, and price.
The limitation appears as the collection grows. Every new spool, finished spool, move, and usage adjustment becomes another manual edit. If the spreadsheet is regularly out of date, it has stopped being an inventory and become a historical guess.
3. Dedicated filament inventory software
Dedicated software becomes useful when filament is part of an operating workflow rather than simply a collection. The goal is not more data entry. It is to make common questions easier: Do I already own this color? Which spool is open? Where is it stored? How much remains? What did it cost?
How to estimate how much filament is left
The most practical method for many makers is weighing the loaded spool and subtracting the empty spool weight, also called the tare weight.
Loaded spool weight − empty spool weight = estimated filament remaining.
For example, if a loaded spool weighs 720 g and the empty spool weighs 220 g, you have approximately 500 g of filament remaining.
Track cost while you track inventory
If you know what a spool cost and how much filament it contained, you can calculate material cost per gram. That becomes useful when you start selling prints or simply want to understand what each project consumes.
When have you outgrown a spreadsheet?
There is no magic spool count. A better test is whether maintaining the system has become harder than getting value from it. You may be ready for a dedicated system when you repeatedly buy colors you already own, cannot quickly locate a spool, frequently wonder whether partial spools have enough material, manage filament across several printers or storage locations, or need material costs for products and orders.
A spreadsheet can remain perfectly good for a long time. The reason to replace it is not because software is newer; it is because the manual system is costing you time or creating bad decisions.
Track your filament inventory in Makeratory
Keep brand, material, color, location, cost, and estimated remaining weight together with the printers, products, and production work that use each spool.
See how Makeratory connects your operation → · Start a free workspace →