A kilogram is how many metres?
The answer depends on two things: the density of the grade and the diameter of the strand. Pick the grade, pick the diameter, then edit any field — the other two follow.
Editing this one
Density used: 1.37 g/cm³ · Polymaker Panchroma™ Matte
The properties on this page are values published in the named manufacturers' data sheets, measured on their grades to the standard printed against each row — not measurements of a ZORVA spool. Use them to compare material classes, not as an acceptance specification.
The arithmetic
Three lines, nothing hidden.
length = mass ÷ (density × π × (diameter ÷ 2)²)
The model volume your slicer reports, multiplied by density, is the grams you pay for. That is why the volume field sits next to the weight field here.
Densities differ enough to matter: from the same 1 kg spool, a lighter grade gives more metres. So do not use one figure for every material.
Diameter tolerance eats into the result too. This assumes the nominal diameter; real filament wanders by a few percent, and over a long print that adds up.
Why does this differ from the length printed on the spool?
Because they used a different density, or the gross spool weight rather than the net weight of plastic. Work from net weight and the published density of that specific grade.
Are 1.75 mm and 2.85 mm interchangeable?
No. The filament path, the drive gear and the hot end are built for one diameter. For the same weight, a 2.85 mm strand is far shorter than a 1.75 mm one because its cross-section is larger.
Can this tell me a part's weight before I print it?
Yes, if you have the volume. Enter the volume your slicer reports — walls, infill and support included — and the weight field gives you the grams.