About this filament calculator

Half-used spools have no reliable markings, and “does this have enough left for the print?” is the question that decides whether you start a 9-hour job. Put the spool on a kitchen scale, enter the gross weight, pick your empty-spool tare, and the tool works back to the remaining filament: net grams, length in metres and volume. Enter a per-part weight from your slicer and it also tells you how many more copies you can print.

Length comes from mass ÷ density ÷ cross-sectional area, so material choice matters: PLA (1.24 g/cm³), PETG (1.27), ABS (1.04), ASA (1.07), TPU (1.21), nylon (1.14), PC (1.20) and carbon- or wood-filled blends are all included, in 1.75 mm and 2.85 mm. Spool tares vary by brand and even by batch — the built-in presets get you close, but weighing one empty spool yourself is worth doing once. Related tools: 3D Print Cost Calculator and the home 3D manufacturing write-up.