How does infill percentage affect material weight?

Infill percentage controls the density of the internal structure. At 0% infill, the part is hollow (only shells). At 100%, it is solid throughout. The relationship is approximately linear for the interior volume: doubling infill roughly doubles the infill material used, while the shell weight stays constant. For most functional parts, 15–25% infill provides adequate strength at a significant material saving.

What is the difference between shell weight and infill weight?

Shell weight is the material used for the outer perimeter walls and top/bottom solid layers — this is always fully solid regardless of infill setting. Infill weight is the material used inside the part at your chosen infill density. For small parts with thin walls, the shell can account for 50–80% of total weight.

How do I find my model volume in a slicer?

In Cura, the model volume is displayed in the object information panel. In PrusaSlicer, right-click the model and select Object Info. In Bambu Studio, it is shown in the plater panel. You can also measure it in your CAD software (Fusion 360: Inspect > Physical Properties; Blender: Properties panel in edit mode).

How accurate is the print time estimate?

The print time estimate here is a rough guide only, based on filament length and average feed speed. Slicer software provides far more accurate estimates by accounting for acceleration, travel moves, retraction, fan cooling delays and layer transitions. Use your slicer's estimate for planning purposes — this calculator is useful for quick comparisons between different infill settings.

Which infill percentage should I use?

General decorative prints: 10–15%. Standard functional parts: 20–30%. High-strength mechanical parts: 40–60%. Parts under significant load or impact: 60–80%. Solid (100%) is rarely needed — a well-designed part at 40% infill with 3–4 perimeters is usually stronger than 100% infill with fewer walls, because perimeter walls contribute more to tensile strength.

Infill Weight Calculator — Material Weight & Filament Length by Infill

Calculate print weight, shell weight, infill weight, filament length and estimated print time from model volume, infill percentage, wall thickness and material type.

Model Volume

Total bounding volume from your slicer or CAD software

Infill Percentage

Percentage of solid fill inside the part — 15–25% is typical for functional parts

Material

Material density affects weight and filament length

Wall Thickness

Total perimeter wall thickness (e.g. 3 walls × 0.4mm nozzle = 1.2mm)

Top / Bottom Layers

Number of solid layers on top and bottom surfaces

How We Calculate This

This calculator breaks the print into shell and infill components, estimates each weight separately, then calculates filament length from volume and material density.

Formulae

Solid weight = Model volume × Material density
Shell fraction = Wall thickness factor + Top/bottom layer factor
Shell weight = Solid weight × Shell fraction
Infill weight = Solid weight × Interior fraction × (Infill % / 100)
Total weight = Shell weight + Infill weight
Filament length = Used volume / Filament cross-section area

Frequently Asked Questions

Related Calculators

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Infill Calculator

Estimate material usage and print time for different infill percentages and patterns.

Wall Thickness Calculator

Calculate wall thickness from number of perimeters and nozzle/line width.

Print Time Estimator

Estimate total print time from layer count, speed and travel moves.

Last updated: March 2026

All calculations are estimates. Always verify settings with test prints before committing to final prints.