Filament length calculator: from weight to meters

Your inputs

Default values are editable examples. Estimates only: check against your printer or slicer.

Worked example

Example: a 1 kg spool of 1.75 mm PLA (density 1.24 g/cm³) holds about 335 m of filament. In 2.85 mm, the same kilogram is only about 126 m.

How it is calculated

Cross-section = π × (diameter ÷ 2)². Length = weight ÷ density ÷ cross-section. With weight in grams, density in g/cm³ and diameter in mm, the result comes out directly in meters.

Limits and checks

Theoretical result: density varies by brand and color, and the real diameter drifts slightly from nominal. Keep a margin for purge, brim and supports.

Frequently asked questions

How many meters are on a 1 kg spool?

About 335 m for 1.75 mm PLA and about 126 m for 2.85 mm. With a density of 1.27 g/cm³ (typical for PETG), 1 kg of 1.75 mm gives about 327 m; with 1.04 g/cm³ (typical for ABS), about 400 m.

How do I know how much filament is left?

Weigh the spool and subtract the empty spool weight, which manufacturers often publish. Otherwise, weigh an empty spool from the same brand.

Which density should I enter?

The one on your filament's data sheet. Common values are around 1.24 g/cm³ for PLA, 1.27 for PETG and 1.04 for ABS, but they vary with the formulation and fillers.

My slicer shows meters, not grams. What now?

Use the reverse calculation, from meters to grams, then the prints-per-spool calculation to see how many prints fit on what is left.

Are my values saved?

No. The calculation runs in your browser: the numbers you type are never sent or stored. As on the rest of the site, page visits and button clicks are measured, without the calculator values.

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