Filament Length / Weight Converter

Filament Density Converter

Convert between filament weight and length using material density. This is useful when your slicer shows filament usage in length but your spool is labeled by weight, or vice versa.

The Formula

Weight = Length × Cross-Section Area × Density

Cross-section area = π × (diameter/2)²

Common Material Densities

• PLA: 1.24 g/cm³ — ~335m per 1kg spool (1.75mm)
• PETG: 1.27 g/cm³ — ~327m per 1kg spool (1.75mm)
• ABS: 1.04 g/cm³ — ~400m per 1kg spool (1.75mm)
• ASA: 1.07 g/cm³ — ~388m per 1kg spool (1.75mm)
• TPU: 1.21 g/cm³ — ~344m per 1kg spool (1.75mm)
• Nylon: 1.14 g/cm³ — ~365m per 1kg spool (1.75mm)

Why 2.85mm Filament Has Less Length

A 2.85mm filament has a cross-section area that is (2.85/1.75)² ≈ 2.65× larger than 1.75mm. So the same weight of 2.85mm filament gives only about 38% of the length compared to 1.75mm.