Boneyard Tools

How many meters are in a 1 kg filament spool

Why a 1 kg spool holds different lengths for PLA, ABS and PETG, how diameter changes the total, and how to estimate the filament left on a partial roll.

Length depends on material, not just weight

A one kilogram spool does not hold a fixed length, because different plastics pack different masses into the same volume. Denser materials fit fewer meters per kilogram. For 1.75 mm filament, one kilogram works out to roughly 335 m of PLA, 400 m of ABS, 327 m of PETG, 344 m of TPU and 365 m of Nylon. That spread is why an ABS spool can outlast a PETG spool of the same weight on a long print.

How diameter reshapes the total

Doubling attention to diameter matters because area grows with the square of the radius. A 2.85 mm strand has about 2.65 times the cross-section of a 1.75 mm strand, so it packs far fewer meters into the same kilogram. One kilogram of 2.85 mm PLA is only around 126 m, against roughly 335 m for 1.75 mm PLA. Always confirm which diameter your printer uses before trusting a length figure from a chart.

Estimating what is left on a partial spool

To gauge a used roll, weigh the spool on a kitchen scale and subtract the empty spool weight, which many brands print on the side or list online. Feed the remaining grams into the weight-to-length mode with the correct diameter and density. The meters it returns tell you whether an upcoming print will finish. Leaving a small safety margin is wise, since the last few grams near the core often feed unevenly.

Turning a slicer estimate into grams

Slicers such as Cura, PrusaSlicer and OrcaSlicer report the filament a model needs, sometimes as a length and sometimes as a weight. If you only have the length, enter it in length-to-weight mode to see the grams, which is the number that matters when comparing against a spool. This is also a quick sanity check on a slicer weight estimate, because a large mismatch usually points to a wrong diameter or density setting.

Frequently asked questions

Why do charts disagree on meters per kilogram?

Most differences come from the density each chart assumed. Brands publish slightly different densities, and moisture or additives shift the real value, so a few percent variation between sources is normal.

Does the empty spool weight matter?

Yes, when weighing a partial roll. An empty cardboard or plastic spool can weigh 150 to 250 g, so subtract it before converting, or your remaining length will read far too high.