Filament calculator
How many grams is that 18 m of PETG? How much is left on a half-used spool? Pick a material and diameter: the math is instant.
Weight → length
Enter a weight in grams.
Length → weight
Enter a length in metres.
How much is left on this spool?
Enter the spool's net weight.
Remaining can't be more than the spool weight.
Tip: most 1 kg spools list a net filament weight: weigh an empty spool once and subtract it for accuracy. Gyroid tracks all of this per spool. Get the app.
How much filament is on a 1 kg spool?
It depends on density and diameter, not just weight. A kilo of 1.75 mm PLA is about 335 m; the same kilo of PETG is about 327 m, and ABS about 400 m because it's the least dense of the common materials. In 2.85 mm the same kilo is roughly a third of the length, since the cross-section is about 2.65 times larger.
How much filament do I need for this print?
Your slicer reports a weight estimate after slicing — use that, and add about 5% for the purge line, skirt, and the occasional restart. If all you have is a length, put it into the length → weight box above. For project-scale budgeting and typical part weights, see how much filament do I need.
How much is left on a part-used spool?
Weigh the whole spool and subtract the empty spool weight. Manufacturers often print that tare weight on the label; if not, weigh one you've finished — cardboard cores tend to run 130-180 g and moulded plastic 180-250 g. Get the number once per brand and the rest is arithmetic, which the box above will do for you.
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