Filament Length to Weight Calculator
Enter a length, a weight or a volume and get the other two for any material and diameter. The table below the calculator lists grams per meter and meters per kilogram for every common filament.
The formulas
weight (g) = length (m) × grams per meter
volume (cm³) = weight (g) ÷ density (g/cm³)
Filament is a cylinder, so its volume is cross-section times length, and its weight is volume times density. The cross-section of 1.75 mm filament is 2.405 mm² (0.02405 cm²); of 2.85 mm, 6.379 mm². That 2.65× ratio is why 2.85 mm spools look so short.
Reference: grams per meter and meters per kilogram
| Material | Density (g/cm³) | 1.75 mm g/m | 1.75 mm m/kg | 2.85 mm g/m | 2.85 mm m/kg |
|---|---|---|---|---|---|
| PLA | 1.24 | 2.98 | 335 | 7.91 | 126 |
| PETG | 1.27 | 3.05 | 327 | 8.10 | 123 |
| ABS | 1.04 | 2.50 | 400 | 6.63 | 151 |
| ASA | 1.07 | 2.57 | 389 | 6.83 | 147 |
| TPU (95A) | 1.21 | 2.91 | 344 | 7.72 | 130 |
| Polycarbonate | 1.20 | 2.89 | 346 | 7.66 | 131 |
| Nylon PA6 | 1.14 | 2.74 | 365 | 7.27 | 138 |
| Nylon PA12 | 1.01 | 2.43 | 412 | 6.44 | 155 |
| PLA-CF | 1.29 | 3.10 | 322 | 8.23 | 122 |
| PETG-CF | 1.30 | 3.13 | 320 | 8.29 | 121 |
| HIPS | 1.04 | 2.50 | 400 | 6.63 | 151 |
| PVA | 1.23 | 2.96 | 338 | 7.85 | 127 |
| Polypropylene | 0.90 | 2.16 | 462 | 5.74 | 174 |
Densities are typical for unfilled, non-foaming grades; the calculator's custom density field takes whatever your spool's data sheet says. Values are rounded to two decimals.
Worked example
A print needs 42 m of 1.75 mm PETG. How much does it weigh and how much space does it take?
- Weight: 42 × 3.05 = 128 g
- Volume: 128 ÷ 1.27 = 101 cm³
- At $24/kg the material is 0.128 × 24 = $3.07
When density matters
Most of the time a generic density is fine, but three cases bite. Filled filaments (carbon fiber, glass, wood, metal) are denser — metal-filled PLA can be 2.0–4.0 g/cm³, so a "1 kg" spool holds a fraction of the usual length. Foaming lightweight PLA is the opposite: about 1.2 g/cm³ on the spool but 0.5–0.6 after it expands in the hotend, so slicer weight estimates are only right if the profile's density matches what's on the reel. And flexible filaments vary between makers (1.15–1.25). If a spool's weight and the slicer's length disagree by more than a few percent, the density in the profile is the first suspect.
To see what's actually left on a partly used spool, use the filament remaining calculator; to turn a weight into a cost, the filament cost calculator.
Frequently asked questions
How much does 1 meter of filament weigh?
For 1.75 mm filament: PLA about 2.98 g, PETG 3.05 g, ABS 2.50 g, ASA 2.57 g, TPU 2.91 g, nylon 2.74 g. For 2.85 mm multiply by about 2.65 — PLA is 7.91 g per meter. The formula is π × (diameter ÷ 2)² × density.
How many meters of filament are in 1 kg?
1.75 mm: PLA about 335 m, PETG 327 m, ABS 400 m, ASA 389 m, TPU 344 m, polycarbonate 346 m, nylon 365 m. 2.85 mm: PLA about 126 m, PETG 123 m, ABS 151 m. Lower-density plastics give more meters per kilogram.
How do I convert filament weight to volume?
Volume (cm³) = grams ÷ density. 100 g of PLA at 1.24 g/cm³ is 80.6 cm³. Slicers report both, and volume is what actually gets extruded — two prints using the same volume in different materials will weigh different amounts.
Why does my slicer's length not match the weight?
The slicer converts with the density and diameter in the filament profile. If either is wrong for your spool — a generic 1.24 g/cm³ for a filled or foaming filament, say — the length is right and the weight is off, or vice versa. Set the density from the spool's data sheet.
What's the density of PLA filament?
About 1.24 g/cm³ for standard PLA. Variants differ: PLA+ and silk PLA are 1.20–1.27, wood-filled around 1.15–1.28, carbon-fiber PLA 1.25–1.32, and lightweight foaming LW-PLA as low as 0.6 after expansion. Check the manufacturer's spec sheet when it matters.
Last reviewed September 7, 2026. Spotted an error or want another calculator? Tell us.