Spool Calculator Estimate the length, volume and weight of filament, wire or rope wound on a spool. Pick a material, set the spool size, and the results update as you type.

PLA Filament
Density: 1.24 g/cm³ · Common 3D printing filament
Cross-section through the axle, to scale Material Flanges Empty space
Estimated length
0 m
Weight
0 kg
PLA Filament, ~1.24 g/cm³ density
Volume
0 cm³
Cubic centimeters
Layers
0
Coils / layer
0
Spool fill
0%
Formula: Length = (Spool Width / Material Diameter) × π × Σ (Inner Diameter + n × 2 × Material Diameter). The maximum theoretical fill for round material is about 90.7% (hexagonal packing); real-world winding is typically 75–85%. Length assumes perfect winding and the fill figure assumes round packing; estimates are approximate and vary with winding tightness.