The calculation
complete jobs per spool = floor(usable ÷ (part + additional waste))
Worked example
With 250 g, 130 g and 60 g left on three spools, a 50 g part, 10 g of additional waste and a 10 g reserve, the plan fits 4, 2 and 0 jobs: 6 complete prints in total.
Keep each spool separate
Adding all your leftovers together can suggest a print is possible when no single spool contains enough material. This planner keeps one job on one spool. It does not assume that a printer can switch automatically or that materials can be mixed. A 100 g part cannot fit on either of two 60 g spools without a separate, validated changeover plan.
Measure before you schedule
Weigh each spool with the same scale, subtract its actual empty-spool weight and enter the net grams. Labels, adapters and reusable spool sides belong in the tare measurement. Use the same sliced file for the per-job value. A different support strategy or object orientation changes material use.
The remaining column includes your reserve and any usable remainder. This is a repeat-job allocation, not an optimizer for differently sized parts. For mixed jobs, calculate the largest job first, update the measured remainder after printing, then plan the next batch.
Common questions
Can I combine the last few grams from different spools?
This tool deliberately does not combine them. Manual swaps and automatic reload systems need their own compatibility and changeover checks.
Why does a spool show zero jobs?
Its remaining grams after reserve are less than one complete job including additional waste.
Further reading
Official or original references for the workflow; these organizations do not endorse this independent tool.