3D Printing Filament Cost Calculator
Use this 3D printing filament calculator to turn a print's weight (from your slicer) into the length of filament used and what it costs. Pick your material and diameter, add your spool price, and get grams, metres, cost, and how much of a spool the print consumes — useful for quoting prints or budgeting a project.
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Calculate filament use and cost
Enter values above and press Calculate to see your result.
Formula used
Filament is a cylinder, so weight and length relate through its cross-section and material density:
Cross-section A = π × (diameter ÷ 2)²Volume = Weight ÷ densityLength = Volume ÷ A
Cost is simply the print's share of the spool:
Cost = Print weight ÷ Spool weight × Spool price
Worked examples
Small print. 25 g of PLA at 1.75 mm ≈ 8.4 m of filament, about $0.55 from a $22 / 1 kg spool.
By length. 100 m of PLA weighs roughly 298 g.
Material matters. The same volume of ABS weighs less than PLA because ABS is less dense.
How to use this calculator
- Read the filament used from your slicer (Cura, PrusaSlicer, etc.) in grams or metres.
- Choose whether you're entering weight or length, and type the amount.
- Select your material and filament diameter.
- Optionally enter your spool price and weight for a cost estimate.
- Press Calculate for weight, length, cost and spool share.
Filament density by material
| Material | Density (g/cm³) | Metres per 1 kg (1.75 mm) |
|---|---|---|
| PLA | 1.24 | ≈ 335 m |
| PETG | 1.27 | ≈ 327 m |
| ABS | 1.04 | ≈ 400 m |
| ASA | 1.07 | ≈ 389 m |
| TPU | 1.21 | ≈ 344 m |
| Nylon | 1.14 | ≈ 365 m |
Lower density means more length per kilogram. Figures are for 1.75 mm filament.
Who should use this calculator
Anyone with a 3D printer who wants to know what a print costs, how much filament a job needs, or whether a spool has enough left. It's handy for hobbyists tracking a project budget and for makers quoting prints for others.
What each input means
- Amount — the filament used, taken from your slicer's estimate.
- Material — sets the density, which links weight and length.
- Diameter — 1.75 mm or 2.85 mm; it changes the cross-section.
- Spool price/weight — used only for the cost figure.
Getting an accurate cost
For a true cost per print, include failed prints, supports, purge/prime, and electricity. The biggest variable is usually failures — add a margin if your print is risky. Slicer weight estimates are quite accurate for the model itself; add a few grams for skirts, brims and purge.
Limitations of this calculator
This converts between weight, length and cost using nominal densities. It does not include printer electricity, wear, labour, or post-processing. Real spool weights vary slightly, and moisture can change material density a little.
Frequently asked questions
How do I know how much filament my print uses?
Your slicer (Cura, PrusaSlicer, Bambu Studio) shows the estimated filament in grams and metres after slicing. Enter that figure here.
How many metres of filament are in a 1 kg spool?
About 335 m of 1.75 mm PLA, more for lighter materials like ABS (~400 m) and less for denser ones.
How much does a typical print cost?
It depends on weight: a 25 g PLA print is roughly $0.50–$0.60 from a $20–$25 spool. Larger prints scale up proportionally.
Does filament diameter affect the calculation?
Yes. For the same weight, 2.85 mm filament is shorter than 1.75 mm because it has a larger cross-section.
Should I include supports and failures in cost?
For an honest cost, yes — add supports, purge and a margin for failed prints. This tool gives the cost of the filament for the weight you enter.