Print Filament Weight Calculator
The mass of a 3D print is the volume of plastic deposited multiplied by the material density. This calculator takes the solid model volume in cubic centimeters, an effective fill fraction that approximates infill, and the filament density in grams per cubic centimeter, then returns the estimated grams of filament used and the corresponding fraction of a 1 kilogram spool. Density is a user-editable input because it varies by material and brand. Treat the result as a transparent first-order estimate; your slicer remains the most precise source because it computes walls, top and bottom layers, and supports individually.
Filament weight formula
Plastic volume = model volume * (fill percent / 100)
Weight (g) = plastic volume * density
Weight (kg) = weight (g) / 1000
Spool share = weight (g) / 1000 * 100
With volume in cubic centimeters and density in grams per cubic centimeter, mass comes out in grams with no extra conversion. The fill fraction is a simplified stand-in for infill plus shells.
Print weight context
- Mass equals volume times density; only the density assumption is editable.
- Set effective fill to 100 percent for a solid part, or lower it to approximate sparse infill.
- Slicers model walls and layers separately, so trust slicer output for final figures.
- Use your data-sheet density for the material, brand, and color you are printing.
- A standard consumer spool holds 1 kilogram of filament net.
Print filament weight: frequently asked questions
How do I calculate filament weight from a print?
Multiply the solid model volume by the effective fill fraction to get the printed plastic volume, then multiply by the material density. Mass equals volume times density. With volume in cubic centimeters and density in grams per cubic centimeter, the result is in grams directly.
How does infill change the weight?
Infill percentage scales the interior volume that is filled with plastic. A 20 percent infill print uses roughly 20 percent of the interior volume in plastic, plus the perimeters and top and bottom layers. This calculator applies your fill fraction to the model volume as a transparent first-order estimate; slicer output is more exact because it models walls separately.
What density should I enter?
Use the resin density from your filament's technical data sheet. Density varies by material, brand, and color, so it stays editable here. Typical nominal values are about 1.24 g/cm3 for PLA, 1.27 for PETG, and 1.04 for ABS.
Why does my slicer report a different weight?
Slicers compute wall, top, bottom, and infill volumes separately and add support and skirt material, so they are more precise. This tool gives a quick estimate when you only know the model volume and an approximate fill fraction.
Can I get the length too?
Yes. Once you have the mass, the companion filament length from weight calculator converts grams to meters using the same density and your filament diameter.
Official sources
- National Institute of Standards and Technology: Office of Weights and Measures (mass, volume, density units).
- RepRap project documentation: reprap.org (filament and slicing reference).
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.