About this tool
Prints Per Spool Calculator is a free, in-browser tool that tells you how many copies of a part a single filament spool will produce, how much filament is left over, and what each print costs in material. It is handy for planning a batch, pricing a small run, or deciding whether one spool covers a job. Everything is computed locally and nothing is uploaded.
The number of prints is floor(spoolWeight ÷ weightPerPrint) — floored because you cannot make a partial copy — and the leftover is spoolWeight − prints × weightPerPrint. If you enter the spool price, the material cost per print is spoolPrice ÷ prints. For a 1000 g spool and a 25 g part that is 40 prints with no leftover.
Use it with the per-print weight from your slicer to see how far a spool stretches, or to set a fair material price per unit. Note it covers filament only; add machine time, electricity and failure allowance separately for a full job cost.