Material · FDM filament

Filament weight, length, and cost calculator

Estimate filament length, mass, and print material cost from the geometry and density of a round filament strand. Switch the known quantity to solve in either direction.

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Calculator

Known amount
Material and spool

Workbench note This is material cost only, not electricity, labor, depreciation, or tax. Independently verify settings that affect equipment, fit, cost, or safety.

01 / METHOD

How to use this filament use tool

  1. Choose whether weight or length is known.
  2. Enter filament diameter and density; common nominal defaults are provided.
  3. Add spool weight and price to estimate cost for the calculated material.

02 / APPLICATIONS

When it is useful

  • Check if the remaining spool is enough
  • Translate slicer grams into meters
  • Estimate the material portion of a quote

03 / MODEL

Assumptions and limitations

Assumptions

  • Filament is treated as a uniform round cylinder.
  • Density is constant across the material.
  • Cost is allocated linearly by mass.

Limitations

  • Real diameter, density, spool tare, purge, supports, and failed prints affect actual usage.
  • This is material cost only, not electricity, labor, depreciation, or tax.

04 / FAQ

Common questions

How is filament length calculated?

Mass is divided by material density and the circular cross-sectional area of the filament.

What density should I use?

Use the manufacturer datasheet when possible. The default 1.24 g/cm³ is a common nominal value for PLA, not a universal value.

Does spool price include the empty spool?

The calculator treats the entered spool mass as net filament. Use the net material weight listed by the seller.