Filament Weight ⇄ Length Converter
Convert grams, meters and cm³ for any filament material & diameter · free, no signup
See Filament Weight ⇄ Length Converter in action
Free Filament Weight ⇄ Length Converter
Filament is sold by weight but used by length, and the two don't convert the same way for every material — PLA, PETG, ABS, TPU and the rest all have different densities, so a 1kg spool of one material holds a noticeably different length than 1kg of another. Pick a material (or enter a custom density), choose 1.75mm or 2.85mm diameter, enter either a weight in grams or a length in meters, and this tool computes the real weight, length and volume together using the actual cylindrical cross-section of the filament.
A second section estimates how much filament is left on a spool: enter the spool's current total weight and its empty (bare spool) weight, and it works out the real remaining filament weight and length — useful for judging whether a partial spool has enough left for the next print.
Key features
Any material or custom density
Presets for PLA, PETG, ABS, ASA, TPU, nylon and polycarbonate, or enter your own density.
1.75mm and 2.85mm diameter
Uses the real filament cross-section area for an accurate conversion.
Weight, length and volume together
Enter either weight or length and get every unit calculated at once.
Remaining-spool estimator
Weigh a partial spool and find out how much filament and how many meters remain.
How to use it
- Choose a material and diameter (or enter a custom density).
- Enter a known weight in grams or length in meters.
- Read the converted weight, length and volume.
- Optionally weigh a spool and enter its gross and empty weight to estimate what's left.
Worked example
Example
1000 g of 1.75mm PLA (density 1.24 g/cm³) converts to about 336 m of filament and 806 cm³ of volume. A partial spool weighing 640 g total, with an empty spool weight of 190 g, has about 450 g — roughly 151 m — of PLA remaining.
Who uses this tool
Makers checking if a spool has enough filament left for a print
Weigh the spool and get a real remaining length instead of guessing from how full it looks.
Anyone comparing material costs by length instead of weight
Convert each material's price-per-kg into a real price-per-meter for a fair comparison.
People buying filament for a specific model
Convert a slicer's reported gram estimate into meters to check it against a spool's remaining length.
Tips for the best results
- Real filament diameter varies slightly (often ±0.02–0.05mm) from the nominal 1.75 or 2.85mm figure, so treat the converted length as a close planning number rather than an exact one.
- Empty-spool weight varies by brand and material (cardboard vs. plastic vs. reusable spools) — weigh your own empty spool once and reuse that figure for accurate remaining-filament estimates going forward.
- When comparing cost between materials, convert to cost-per-meter or cost-per-cm³ rather than cost-per-kg alone, since denser materials like PETG or nylon pack less length into the same weight than PLA.
Common mistakes to avoid
- Weighing a mostly-empty spool without ever having weighed the bare spool, and guessing the empty weight — even a 20–30g guessing error meaningfully skews the remaining-filament estimate.
- Assuming every filament of the same material has identical density — pigments and fillers (like carbon-fiber or wood-filled blends) shift real density, so use a custom density figure for those if known.
- Mixing up 1.75mm and 2.85mm diameter — the cross-section area (and therefore the length-per-gram) differs by more than double between them.
Why use AZRS QuickFix?
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Frequently asked questions
How many meters are in a 1kg spool of PLA?
About 330–336 m at 1.75mm diameter, depending on the exact density used; this tool computes the real figure from your chosen density.
Does filament diameter (1.75mm vs 2.85mm) change the weight-to-length ratio?
Yes — significantly. The cross-section area of 2.85mm filament is more than 2.6× that of 1.75mm, so the same weight covers a much shorter length at 2.85mm.
How accurate is the remaining-spool estimate?
As accurate as the two weights you enter — using a kitchen or postal scale and a known empty-spool weight gives a genuinely reliable figure.
Can I use a custom density?
Yes, for filled, composite or unusual filaments not covered by the standard material presets.
Is my data saved anywhere?
No, all figures are entered and calculated locally in your browser.