Filament Length ↔ Weight Calculator
Convert filament weight to length, or length to weight, using the material's density and diameter. 1 kg of 1.75 mm PLA is about 335 m.
Estimates only. Check numbers against your own slicer, scale and electricity bill. Some links on this page may be affiliate links.
The formula
Filament is treated as a solid cylinder. Cross-section (cm²) = π × (diameter in cm ÷ 2)². Grams per metre = density × cross-section × 100. Length = grams ÷ grams per metre, and weight = metres × grams per metre. For 1.75 mm PLA at 1.24 g/cm³ that is about 2.98 g per metre.
Metres per 1 kg spool
| Material | Density (g/cm³) | 1.75 mm | 2.85 mm |
|---|---|---|---|
| PLA | 1.24 | 335 m | 126 m |
| PETG | 1.25 | 333 m | 125 m |
| ABS | 1.04 | 400 m | 151 m |
| ASA | 1.07 | 389 m | 146 m |
| TPU 95A | 1.21 | 344 m | 130 m |
Density sources
- PLA 1.24 g/cm³: Prusament PLA technical data sheet and Bambu Lab PLA Basic TDS (ISO 1183).
- PETG 1.25 g/cm³: Bambu Lab PETG Basic and Polymaker PolyLite PETG data sheets.
- ABS ~1.04 g/cm³: Polymaker PolyLite ABS data sheet (some brands list 1.05).
- ASA (~1.07) and TPU 95A (~1.21) are typical values — check your brand's data sheet and edit the density field.
Related: print cost calculator · AMS purge waste
FAQ
How long is 1 kg of PLA filament?
About 335 m for 1.75 mm PLA and about 126 m for 2.85 mm PLA, assuming a density of 1.24 g/cm³.
Why does ABS give more metres per kg?
ABS is less dense (about 1.04 g/cm³) than PLA (1.24), so the same weight makes a longer strand — roughly 400 m per kg at 1.75 mm.
Is the spool weight included?
No. Use the net filament weight. Weigh the full spool and subtract the empty spool weight to find what is left.