🧵 Filament Calculators
Calculate filament usage, cost, weight, spool length, and density for any 3D print project.
All Filament Tools
Understanding Filament: Types and Properties
3D printing filament is a thermoplastic material supplied on a spool, most commonly in 1.75 mm or 2.85 mm diameters. The two most popular materials are PLA (polylactic acid) and ABS (acrylonitrile butadiene styrene). PLA is derived from renewable sources such as corn starch, prints at 180–220°C, requires no heated bed, and is the most beginner-friendly material. ABS prints at 220–250°C, requires a heated bed (90–110°C), and is prone to warping without an enclosure, but produces parts with better heat and impact resistance. PETG (polyethylene terephthalate glycol) has emerged as a middle ground — nearly as easy to print as PLA but with ABS-like strength and temperature resistance.
Filament Density and Weight Calculations
Different filament materials have different densities, which affects both the weight of a printed object and the length of filament on a spool. PLA has a density of approximately 1.24 g/cm³; ABS is lighter at 1.04 g/cm³; PETG is 1.27 g/cm³; TPU (flexible filament) varies widely at 1.20–1.25 g/cm³. To convert filament volume (from slicer software, typically in mm³) to weight in grams, multiply by the material density in g/mm³ (density in g/cm³ ÷ 1000). A standard 1 kg spool of 1.75 mm PLA contains approximately 335 metres of filament.
Calculating Filament Usage and Cost
Most slicer software reports filament usage in both length (metres) and weight (grams). To calculate material cost for a print, divide the print weight by the total spool weight and multiply by the spool price. For example, if a print uses 47 g of filament from a 1 kg spool costing $25, the material cost is (47 ÷ 1000) × $25 = $1.18. Infill percentage significantly affects filament usage: a part printed at 20% infill uses roughly 50–60% of the filament that a solid 100% infill part would use, while still providing adequate strength for most applications.
Spool Remaining Estimates
Accurately estimating the remaining filament on a partial spool prevents mid-print failures. If you know the spool's empty weight (usually marked on the spool or findable online for common brands), weigh the loaded spool on a kitchen scale and subtract to get remaining filament weight. For a 1.75 mm PLA spool, divide the remaining grams by 1.24 (density) to get remaining volume in cm³, then divide by the cross-sectional area of the filament (π × 0.0875² cm² = 0.024 cm²) to get remaining length in centimetres. Our spool length calculator automates this conversion.