Filament Cost Calculator

Calculating filament cost accurately helps you price prints, manage your spool inventory, and compare material costs across different filament types.

Core formula: Filament Cost = (Print Weight in grams ÷ Spool Weight in grams) × Spool Price

Or using length: Filament Cost = (Filament Length Used in meters ÷ Total Spool Length) × Spool Price

Weight-to-length conversion: Length (m) = Weight (g) ÷ (π × (Diameter in mm ÷ 2)² × Density in g/cm³)

The units in that line look wrong until you notice that a cross-section in mm² times a length of one metre is exactly one cm³. So the bracket works out to grams per metre, and dividing grams by it leaves metres.

For 1.75mm PLA (density ≈ 1.24 g/cm³): 1 kg of filament ≈ 335 meters

For 1.75mm PETG (density ≈ 1.27 g/cm³): 1 kg of filament ≈ 327 meters

Worked example: A print uses 87 g of PLA. The 1 kg spool cost $22. Cost = (87 ÷ 1000) × $22 = $1.91 in filament

For a full cost estimate, add electricity: Electricity Cost = Printer Wattage (kW) × Print Hours × kWh Rate Example: 0.2 kW × 6 hours × $0.13/kWh = $0.16 Total material + power: $1.91 + $0.16 = $2.07

Common filament densities:

• PLA: 1.24 g/cm³ (~335 m/kg at 1.75mm)
• PETG: 1.27 g/cm³ (~327 m/kg at 1.75mm)
• ABS: 1.04 g/cm³ (~400 m/kg at 1.75mm)
• TPU: 1.21 g/cm³ (~343 m/kg at 1.75mm)

Typical cost ranges per kg:

• Budget PLA: $15–$20
• Quality PLA/PETG: $20–$30
• Engineering filaments (ASA, PC, Nylon): $30–$60
• Carbon fiber or specialty: $60–$120+