Infill Material Volume Calculator
Estimate how much filament an FDM print consumes from the model's solid volume and the infill percentage. Because walls, top and bottom layers stay solid whatever the infill, the tool treats a shell allowance as fully solid and only fills the remaining interior, then converts the plastic volume to weight and length.
Enter Values
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter the model's solid (watertight) volume in cm³ — most slicers and CAD tools report this.
- Enter the infill percentage you plan to slice at (0–100%).
- Optionally adjust the shell allowance (default 15%) and filament density (default 1.24 g/cm³ for PLA).
How it works
Material volume = model volume × (shell% + (1 − shell%) × infill%). The shell fraction is counted as solid; the rest of the interior is scaled by the infill percentage. That volume is multiplied by the filament density to get grams, and divided by the 1.75 mm filament cross-section (π/4 × 0.175² ≈ 0.02405 cm²) to get metres of filament.
Worked example
Worked example. A 50 cm³ model at 20% infill with a 15% shell allowance uses 50 × (0.15 + 0.85 × 0.20) = 50 × 0.32 = 16 cm³. At 1.24 g/cm³ that is 19.84 g, or 16 ÷ 0.02405 ≈ 665 cm ≈ 6.653 m of 1.75 mm filament.
Common mistakes
- Using the bounding-box volume instead of the true solid volume of the model — that hugely overestimates the plastic used.
- Assuming material scales linearly with infill: the solid shell means even 0% infill still uses roughly the shell fraction of the volume.
- Applying a PLA density to a different material — PETG (~1.27) and ABS (~1.04) differ enough to change the weight.
Frequently asked questions
Why doesn't 0% infill give 0 grams?
Even with no infill the print still has solid perimeters, top and bottom layers. The shell allowance (default 15%) accounts for this, so 0% infill still uses roughly the shell fraction of the model volume.
Is this as accurate as my slicer?
No — it is an approximation. The real shell fraction depends on wall count, layer height and part size. Slice the model for the definitive figure; this tool is for quick estimates and cost planning.
Related tools
- 3D Print Time Estimator
- Support Material Volume Estimator
- Filament Remaining Calculator
- 3D Print Energy Cost Calculator
- Print Shrinkage Compensation Calculator
- Sheet Yield / Parts per Sheet Calculator
Explore more in 3D Printing & Fabrication.
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.