Filament Length to Weight Converter
Turn grams of filament into meters, or a slicer's meters into grams. Pick your diameter and a density from a named product's data sheet, or enter your own.
How it works
grams_per_meter = density × π × (diameter ÷ 2)²
One meter of filament is a cylinder 1000 mm long. Its volume in cubic centimeters equals its cross-section area in square millimeters, so multiplying that area by the density in g/cm³ gives grams per meter. Worked example: 1.75 mm filament has a cross-section of π × 0.875² = 2.405 mm². At 1.24 g/cm³ that is 2.983 g per meter, so 1000 g is about 335 m. At $24 per kg, each meter costs about 7.2 cents.
Real filament is not perfectly round or exactly its nominal diameter, and density varies by product, color and additive. Expect a few percent of difference from a weighed spool.
Density presets and where they come from
| Material | Product data sheet | Density |
|---|---|---|
| PLA | Bambu Lab PLA Basic (TDS V3.0) | 1.24 g/cm³ |
| PETG | Bambu Lab PETG Basic (TDS V3.0) | 1.25 g/cm³ |
| ABS | Bambu Lab ABS (TDS V3.0) | 1.05 g/cm³ |
| ASA | Bambu Lab ASA (TDS V3.0) | 1.05 g/cm³ |
| TPU (flexible) | Bambu Lab TPU 95A HF (TDS V1.0) | 1.22 g/cm³ |
| Polycarbonate (PC) | Bambu Lab PC (TDS V2.0) | 1.2 g/cm³ |
| Nylon (PA) | Prusament PA11, unfilled (TDS v1.0, July 2026) | 1.02 g/cm³ |
These are one product each, not values for every filament of that type. The same products appear with their heat and strength data in the material comparison.
Frequently asked
- How many meters are in a 1 kg spool of 1.75 mm PLA?
- About 335 m at a density of 1.24 g/cm³, the figure on Bambu Lab's PLA Basic data sheet. A different PLA with a different density, or filament slightly over or under 1.75 mm, gives a slightly different length.
- Why does PETG or ABS give a different length for the same weight?
- Length depends on density. A lighter material packs more length into each gram: at 1.75 mm, ABS at 1.05 g/cm³ is about 2.53 g per meter, while PLA at 1.24 g/cm³ is about 2.98 g per meter.
- My slicer reports filament in meters. How do I get the cost?
- Switch to length to grams, enter the meters, then follow the link to the filament cost calculator, which carries the grams over and lets you add waste. Or enter a price per kg here for the cost of that length directly.
- How do I convert what is left on a spool?
- Weigh the spool and subtract the empty spool weight in the remaining filament calculator first. The grams it gives are net filament, which is what this converter needs.