What is filament density?
Short answer
Density is how heavy a filament is for its size, in grams per cubic centimetre (g/cm³). It matters because filament is sold by weight: a denser material gives you fewer metres per kilogram, so the same spool prints fewer parts.
Typical density by material
The middle value across the filaments we list for each material. Always check the range for your own filament.
| Material | Density |
|---|---|
| PLA Polylactic acid | 1.24 g/cm³ |
| PETG Polyethylene terephthalate glycol | 1.27 g/cm³ |
| TPU Thermoplastic polyurethane | 1.21 g/cm³ |
| ABS Acrylonitrile butadiene styrene | 1.04 g/cm³ |
| ASA Acrylonitrile styrene acrylate | 1.07 g/cm³ |
| PA6 Nylon 6 (polyamide 6) | 1.14 g/cm³ |
| PA12 Nylon 12 (polyamide 12) | 1.01 g/cm³ |
| PC Polycarbonate | 1.20 g/cm³ |
| PP Polypropylene | 0.90 g/cm³ |
| PCTG Polycyclohexylenedimethylene terephthalate glycol | 1.23 g/cm³ |
| PEI Polyetherimide | 1.27 g/cm³ |
| PET Polyethylene terephthalate | 1.34 g/cm³ |
| HIPS High-impact polystyrene | 1.04 g/cm³ |
| TPE Thermoplastic elastomer | 1.20 g/cm³ |
Guide
Why density matters
- Length per spool: a 1 kg spool of a light material such as ABS holds more metres than a 1 kg spool of denser PETG.
- Part weight: the same model weighs more in a denser material.
- Slicer estimates: slicers use density to turn filament length into grams and cost, so set it correctly for accurate estimates.
Filled filaments, such as those with metal, carbon fibre or glow powder, are often denser than the base plastic.
Density questions
What is the density of PLA?
Most PLA is around 1.24 g/cm³.
What is the density of PETG?
Most PETG is around 1.27 g/cm³.
Which filament has the lowest density?
Why does density sometimes say "typical value"?
Some makers don't publish a density. Where it's missing we show the typical value for the material and label it as such.