Filament Length Calculator

Understanding Your Spool's Remaining Filament

For 3D printing hobbyists who need to know how many meters of PLA, ABS, or PETG remain on a spool before printing, this tool instantly turns weight and diameter into usable length. Planning prints becomes much easier when you can accurately estimate if you have enough material for your next project. This calculator streamlines your workflow, helping to prevent mid-print filament run-outs.

The core principle behind this calculator is simple: Filament length = mass / (density * pi * (d/2)^2). This formula accounts for the specific density of your material (PLA 1.24, ABS 1.04, PETG 1.27 g/cm3), ensuring precise results for common filament types.

How to Use This Filament Length Calculator

1. Enter the spool mass in grams. This is typically the weight of the filament only, or you can subtract the known weight of an empty spool from a full spool's weight.
2. Choose the filament diameter. Select either 1.75 mm or 2.85 mm, the two most common sizes.
3. Select the material or input a custom density. Choose from pre-set options like PLA, ABS, or PETG, or enter a specific density for less common materials.
4. View the live length result. The calculated filament length in meters will update instantly. You can copy it with the provided button if needed.

FAQ

Q: How do I calculate filament length for a spool of PLA?

A: Input the mass in grams, diameter in mm, choose PLA, and the calculator uses PLA density 1.24 g/cm³ to compute the length.

Q: What is the formula used in this calculator?

A: Filament length = mass / (density * pi * (d/2)^2), with densities PLA 1.24, ABS 1.04, PETG 1.27 g/cm3.

Q: Does the calculator work for other filaments like ABS or PETG?

A: Yes, it includes densities for ABS 1.04 g/cm³ and PETG 1.27 g/cm³, and you can enter any custom density.

Q: What happens if I enter a negative mass or diameter?

A: The tool shows an error message and does not compute a length for non-positive inputs.