Filament Cost per Gram: Calculate the Material Used in a 3D Print

Reviewed November 9, 2026

Divide the price you paid for the filament by its net filament weight in grams. Then multiply the result by the grams consumed. For a $24 spool containing 1,000 g of filament, the material costs $0.024 per gram; a 120 g print uses about $2.88 of filament before waste, shipping, electricity or other costs.

Hypothetical arithmetic, not a current product price.

1. Use net material weight, not the spool's total weight

A 1 kg package usually refers to 1,000 g of material when the product lists net filament weight. The plastic or cardboard reel may weigh more; do not divide by the combined reel and material weight. A 750 g spool at $24 costs $24 ÷ 750 = $0.032 per gram, not $0.024. Check the specific label and use the actual paid price. If you want delivered material cost, include the share of shipping and taxes you choose and label that assumption.

2. Decide which grams to count

For a single print, use your slicer's estimated material mass as an estimate, not a measured outcome. Include supports, brim, purge or other material if the slicer reports them separately. Do not add them again if the displayed total already includes them. For a completed job, measured material consumption can differ; keep a small record if actual costs matter.

Model only: 120 g × $0.024 = $2.88.
Model plus separately reported waste: (120 g + 30 g) × $0.024 = $3.60.
Failed attempt: another 120 g of the same material would add $2.88; only add it if it actually happened or clearly label it as a scenario.

Different colors or materials?

Calculate each material separately: its grams used × its own price per gram, then sum the results. If your slicer already includes purge in each material's totals, do not add it twice. This method does not predict a universal purge amount or failure rate.

Material cost is only one part of a quote

Electricity, machine wear, labor, packaging, shipping, taxes and failed prints may matter to your full cost. A $3.60 filament estimate does not mean a job costs $3.60 to produce. Account for those separately using your own inputs, and distinguish cost from selling price.

Quick check before comparing spools

Write the net grams, quantity, paid price and whether shipping is included. Convert kilograms to grams (1 kg = 1,000 g). Check whether multipack prices are for one spool or several. This calculation provides no claim about print quality, compatibility or brand performance.

For another practical task, see the PETG stringing checklist. No printer, filament or pricing test is claimed here.