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How much filament will your print take?
Updated
Your slicer tells you a print needs so many grams. A 1 kg spool of 1.75 mm PLA holds about 335 meters. Type in the grams to get meters and spools. It is an estimate: it assumes PLA at 1.24 g/cm3.
Filament estimate: grams to meters and spools
This is an estimate for PLA. It uses a density of 1.24 g/cm3 and 1.75 mm filament. Other plastics have other densities, so the length will differ. Plan a little extra for purging, supports and failed first tries.
The formula
Filament is a long cylinder. Its cross-section is pi x (0.175 cm / 2) squared, which is about 0.0241 cm2. One gram of PLA at 1.24 g/cm3 takes up 1 / 1.24 cm3. Divide that volume by the cross-section and you get about 0.335 m of filament per gram.
| Print needs | Length of 1.75 mm PLA | Share of a spool |
|---|---|---|
| 5 g | About 2 m | 0.005 of a 1 kg spool |
| 15 g | About 5 m | 0.015 of a 1 kg spool |
| 50 g | About 17 m | 0.05 of a 1 kg spool |
| 100 g | About 34 m | 0.1 of a 1 kg spool |
| 250 g | About 84 m | 0.25 of a 1 kg spool |
| 1,000 g | About 335 m | 1 of a 1 kg spool |
- 15 g5 m
- 50 g17 m
- 100 g34 m
- 250 g84 m
Why a spool runs out early
- Purge and priming. Every print starts with a purge line.
- Color changes. Multi-color printing flushes old color out at each change. That can add a lot on small prints. See the multi-color guide.
- Supports and brims count toward the total, and the slicer includes them.
- Failed first tries. Plan on a few while you learn.
Other plastics
The same grams of a different plastic give a different length, because density differs. Treat this page as a PLA estimate. Prusa's PLA page calls PLA one of the easiest materials for beginners, which is why every printer on this site lists it. For ABS and ASA, see enclosed vs open.
Printers that start you with small spools in mind: the Bambu Lab A1 mini for small parts. Caveat: a 180 mm build limit. For bigger parts, see the fit checker.