🧵 Filament Weight & Length Calculator
Enter a weight or a length, pick your material and diameter, and get the filament's weight, length and volume.
Weight
1,000 g
1 kg
Length
335.3 m
1,100 ft
Volume
806.5 cm³
Filament is a cylinder, so weight = length × cross-section area (π·(d/2)²) × density. A 1 kg PLA (1.24 g/cm³) 1.75 mm spool is about 335 m. Densities vary a little by brand — check your spool's datasheet for precision. 🔒 In your browser.
How the filament weight & length calculator works
Filament is a uniform plastic cylinder, so its weight, length and volume are locked together by geometry. The cross-section area is π·(d/2)² for diameter d; multiply by length for volume, and by the material's density for weight. The tool converts either way — weight to length or length to weight — using the density of your chosen material (PLA, PETG, ABS and more) and the standard 1.75 mm or 2.85 mm diameter.
A 1 kg spool of PLA (density 1.24 g/cm³) in 1.75 mm holds about 335 m; the same weight in a less-dense plastic like ABS is longer, and in thick 2.85 mm filament it's much shorter. Densities vary a little between brands and colours, so for a precise figure use the value on your spool's datasheet.
Frequently asked questions
How much filament is on a 1 kg spool?
For 1.75 mm PLA (1.24 g/cm³), about 330–335 m. Lower-density plastics like ABS give a bit more length per kilogram, and 2.85 mm filament gives far less (roughly a third), because the strand is thicker.
How do I convert filament length to weight?
Weight = length × cross-section area × density, where the area is π·(d/2)². The tool does it for you — enter the length, material and diameter and it returns the weight and volume.
How much filament does my print use?
Your slicer (Cura, PrusaSlicer, OrcaSlicer, Bambu Studio) reports the estimated filament length or weight for a sliced model. Enter either here to convert to the other and to a volume, and use the cost tool to price it.
Why does the filament density matter?
Because weight depends on it directly: the same length of a denser plastic weighs more. Using the right density (PLA 1.24, PETG 1.27, ABS 1.04 g/cm³, etc.) makes the length↔weight conversion accurate — the wrong one skews the result.
How do I know how much filament is left on a spool?
Weigh the spool, subtract the empty spool's weight (often printed on it) to get the filament weight, and enter that here to get the remaining length. It's the reliable way to tell if a print will finish.