806.45 cm³ for PLA at 1.24 g/cm³. But the answer is different for every material, and the spread is over three to one.
| Material | Density | Volume in 1 kg |
|---|---|---|
| Polypropylene | 0.9 g/cm³ | 1,111.11 cm³ |
| ABS | 1.05 | 952.38 cm³ |
| PA6 | 1.14 | 877.19 cm³ |
| PLA | 1.24 | 806.45 cm³ |
| PETG | 1.27 | 787.40 cm³ |
| Metal-filled PLA | 3.2 | 312.50 cm³ |
Why volume is the number that matters
A printed part is a shape, not a mass. Two kilograms of different filaments do not build the same amount of object, and the difference is not small: a kilogram of polypropylene contains more than three and a half times the printable volume of a kilogram of metal-filled PLA.
Slicers report mass because the spool is sold by mass. But when you are deciding whether a spool will cover a job, or comparing what two materials cost for the same part, volume is the honest unit.
It is also the number your slicer computes first
The slicer knows the toolpath, so it knows extruded volume exactly. It then multiplies by the density in the filament profile to get the grams it displays. Every mass estimate you have ever read off a slicer is a volume figure with a density applied to it.
Which means: get the density field wrong and the volume is still right while the mass is wrong. That is why a profile left on PLA's 1.24 while a matte or filled grade is loaded produces confident, consistent, incorrect estimates.
Converting between the two
Volume in cubic centimetres multiplied by density in grams per cubic centimetre gives mass in grams. Nothing more complicated than that, and it works in either direction.
A 60 mm cube at 20% infill contains 57,824 mm³ of extruded plastic — 57.82 cm³, or about a fourteenth of a PLA spool.
The one case where volume misleads
Foaming filaments. LW-PLA is stored in the data layer at 0.4 to 1.24 g/cm³, and that is not a manufacturing tolerance — it is a printing choice. The material expands when it is run hot, so the density of the filament on the reel and the density of the finished part are different numbers. A spool of it holds a fixed volume of unexpanded plastic and an entirely elastic volume of printed object, which is the point of the material and the reason no single figure fits it.
Compute the volume for any density in the length and weight converter, and look up per-material density bands on the materials index.