Filament Calculator
Every 3D printer slicer (Cura, PrusaSlicer, Bambu Studio, OrcaSlicer) tells you how much filament your print will use, but converting between grams, cubic centimeters, meters of filament, and dollars requires knowing the material density and filament diameter. This 3d printer filament calculator handles the conversions for PLA, ABS, PETG, TPU, nylon, ASA, and wood-filled PLA in both 1.75 mm and 2.85 mm diameters, plus it estimates cost per print with a failure-rate buffer.
How the 3D Printer Filament Calculator Works
The math relies on three core values:
- Material density (grams per cubic centimeter)
- Filament cross-section area (derived from diameter)
- Print volume (cm³), weight (g), or length (m)
Given any one of weight/volume/length, the other two can be computed:
- Weight (g) = Volume (cm³) x Density (g/cm³)
- Length (m) = Volume (cm³) x 1000 / (Pi x radius² in mm²) / 1000
PLA Filament Calculator Reference
PLA has a density of 1.24 g/cm³. A 50 g PLA print therefore uses:
- Volume: 50 / 1.24 = 40.3 cm³
- Length on 1.75 mm filament: 40.3 * 1000 / 2.405 / 1000 = 16.76 meters
- Length on 2.85 mm filament: 40.3 * 1000 / 6.379 / 1000 = 6.32 meters
Use this pla filament calculator reference to verify your slicer output or double-check material orders before a big batch.
Material Density Reference
| Material | Density (g/cm³) |
|---|---|
| PLA | 1.24 |
| ABS | 1.04 |
| PETG | 1.27 |
| TPU | 1.21 |
| Nylon (PA6, PA12) | 1.14 |
| ASA | 1.07 |
| Wood-filled PLA | 1.15 |
Specialty filaments (carbon fiber reinforced, metal-filled, glow-in-the-dark) can vary from 1.0 to 4.0 g/cm³. Check the manufacturer's technical data sheet for exact density.
Filament Calculator STL Output
If you're using a filament calculator stl workflow, your slicer converts the STL mesh into G-code and reports the three key numbers:
- Filament used (m) - total length the extruder will push
- Filament used (g) - mass of plastic deposited
- Estimated cost - if you've set a spool price in slicer settings
This calculator cross-checks slicer output, especially helpful if you're comparing materials or evaluating a print across different nozzle sizes and infill settings.
Filament Calculator Weight Explained
Most hobbyists track usage by filament calculator weight because 1 kg spools are the standard unit sold. A 200 g print consumes 20% of a $25 spool, or $5 of material. Track grams per print to:
- Estimate production cost for products you sell
- Decide when to load a fresh spool before a long print
- Compare material efficiency across infill densities
Cost per Print
Filament cost per gram varies by material:
| Material | Spool price (1 kg) | Cost per gram |
|---|---|---|
| PLA | $18-30 | $0.018-0.030 |
| PETG | $22-35 | $0.022-0.035 |
| ABS | $20-30 | $0.020-0.030 |
| TPU | $30-50 | $0.030-0.050 |
| Nylon | $40-80 | $0.040-0.080 |
| Specialty (CF, metal) | $60-150 | $0.060-0.150 |
Add 5-15% failure buffer based on your print experience. A new user running a 48-hour print should buffer 15%; a veteran with a tuned printer can get away with 2-3%.
Reducing Filament Consumption
- Drop infill from 20% to 10-15% for non-structural parts (cuts plastic ~25%)
- Use tree or gyroid infill for better strength-to-weight
- Lower wall count from 3 to 2 shells when strength isn't critical
- Eliminate supports with design-for-print orientation
- Hollow out solid volumes with strategic cavities in CAD