Makeratory Resources / Filament planning
Filament planning guide
How many 3D prints can you get from a spool of filament?
Turn slicer grams into a realistic production estimate before you promise a quantity or start a batch.
The basic formula
Usable filament grams ÷ grams per finished print = theoretical prints per spool.
If a 1,000 g spool is truly full and one finished item uses 82 g, the theoretical result is 12.2 prints. In practice you would plan for 12 at most, and often fewer after purge, supports, test pieces, failed starts, and the small amount you may not want to consume at the end of a spool.
Use usable weight, not the label alone
A partially used spool should be estimated from the filament that is actually left. Weigh the loaded spool, subtract the empty-spool tare weight, and use the remainder as your starting inventory.
Use slicer weight for the production version
The useful grams-per-print number is the sliced version you actually intend to manufacture: the chosen material, infill, walls, supports, brim, color changes, and quantity on the plate. A decorative prototype and a production-ready version can consume very different amounts.
Add a waste allowance before committing the spool
A simple planning method is to reserve a percentage of the spool for expected waste. For example, reserving 8% of a 1,000 g spool leaves 920 g of planned usable material. At 82 g per item, that supports 11 complete prints rather than the theoretical 12.
Multi-color prints need a per-color estimate
For AMS or other multi-material work, do not divide total grams by one spool. Track each color or material separately, including purge and transition waste. A job can have enough total filament while still running out of the one color that matters.
For an order, calculate all units before starting
Once the quantity grows beyond a few pieces, move from "prints per spool" to a complete material requirement: grams per item × order quantity, plus expected waste, plus a small operational buffer.
Connect the estimate to real inventory
Makeratory is built for the point where remaining spool amounts, product recipes, and production quantities need to stay connected instead of being recalculated from scratch for every batch.