How to Calculate 3D Printing Cost Per Gram
Cost per gram is the foundation of 3D print quotes, but most makers forget electricity, machine wear and labor when dividing filament price by spool weight.
The simple filament-only calculation
Basic cost per gram = filament spool price ÷ usable grams. A $20 PLA spool with 1,000g yields $0.02 per gram if every gram is usable. In reality, purge waste, failed prints and stuck supports reduce yield to 900–950g, raising true cost to $0.021–$0.022 per gram.
This filament-only number is a starting point, not a selling price. It covers plastic material cost but ignores electricity, machine depreciation, labor and profit.
Adding electricity cost per gram
A desktop FDM printer draws 50–200 watts during printing. At $0.12/kWh, a 100-watt printer costs $0.012 per hour to run. Divide hourly electricity by grams extruded per hour (typically 10–15g/hr at 50mm/s) to get electricity cost per gram.
Example: $0.012 per hour electricity ÷ 12 grams per hour = $0.001 per gram electricity cost. This adds $0.001–$0.002 per gram depending on print speed and nozzle temperature.
Machine depreciation per gram
A $300 printer that lasts 2,000 print hours costs $0.15 per hour depreciation. If that hour produces 12 grams of parts, machine wear is $0.0125 per gram. Larger industrial printers with higher upfront costs and longer lifespans may cost more per hour but spread over higher throughput.
Nozzles, belts and hotends wear out and need replacement. Budget $50–$100 annual maintenance per printer and divide by annual kilograms produced.
Labor cost per gram
Setup, bed leveling, removing supports, post-processing and quality checks are labor. A 4-hour overnight print may only need 15 minutes of hands-on time, but that 15 minutes at $20/hour is $5. Divide $5 by print grams to get labor cost per gram.
For complex multi-part assemblies, labor can exceed material cost. Always track actual minutes spent, not just print runtime.
Total cost per gram formula
Total cost per gram = (filament cost + electricity + machine depreciation + labor + waste allowance) ÷ finished grams. Use this total when quoting print jobs, not just the filament price.
Typical all-in cost per gram ranges: PLA $0.03–$0.06, PETG $0.04–$0.08, ABS $0.04–$0.07. Specialty filaments like carbon fiber or flexible TPU can reach $0.15–$0.30 per gram.
Per-gram vs. per-print-job pricing
Cost per gram is useful for comparing material efficiency across prints, but most customers prefer per-job quotes. A 50-gram print at $0.05/g total cost is $2.50 cost, but you should charge $8–$12 retail to cover overhead and profit.
Use the 3D Printing Cost Calculator to convert grams and hours into a full quote including margin. Cost per gram is an internal metric, not a customer-facing price.