🧵 3D printing

3D Filament Length & Weight Calculator

Convert filament weight to length for PLA, PETG or ABS. Check whether your spool contains enough material for the next print and estimate its value.

✓ Free calculator✓ No sign-up✓ Instant results

Calculation inputs

Change any value for an instant recalculation.

Calculation inputs are saved locally in your browser.

How is it calculated?

Mass divided by density gives volume. Length follows by dividing that volume by the filament cross-sectional area: metres = (mass / density) / (π × (diameter in cm / 2)²) / 100.

Material densities are typical examples. Manufacturer specifications may differ, and empty spool weight must be excluded.

Frequently asked questions

Can I include the weight of the spool?

No. Subtract the empty spool weight to avoid overestimating available filament.

Does every PLA filament have the same density?

No. Density can vary by manufacturer and additives. Refer to the material data sheet when accuracy matters.

Equipment related to this calculation

Practical, non-promotional buying considerations. Future partner recommendations will be clearly disclosed.

Digital scale

Weigh the spool and subtract its empty weight rather than trusting the original package weight.

Filament

Check material, diameter and density since they affect weight-to-length conversion.

Frequently asked questions

Why does filament length depend on material?

PLA, PETG and other plastics have different densities, so the same weight can correspond to different lengths.

How do I know whether a spool is sufficient?

Compare remaining material against the slicer estimate, allowing extra for purge, supports and possible failed prints.