Filament length & weight converter
How long is 500 g of PETG? How many grams in 100 m of 1.75 mm PLA? This converter answers both directions using real material densities.
The formula
Filament is a cylinder, so volume = π × r² × length. With the radius in centimetres, multiplying by density (g/cm³) gives grams:
weight = (length_mm ÷ 10) × π × (diameter_mm ÷ 20)² × density
As a sanity check: 1 kg of 1.75 mm PLA at 1.24 g/cm³ is about 335 m, and 1 kg of PETG is about 327 m. If your result is far from that, check the density and diameter.
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FAQ
How many metres is 1 kg of PLA?
About 335 m for 1.75 mm PLA at 1.24 g/cm³. PETG is about 327 m, ABS about 400 m because it is less dense.
Does 2.85 mm filament hold more grams per metre?
Yes. 2.85 mm filament is about 2.65× the cross-section of 1.75 mm, so the same weight is much shorter — around 126 m per kg of PLA.