In short
- In practice you use about 900 to 950 grams of a 1 kg spool for your prints.
- That is enough for about 23 phone stands, 118 keychains or 7 plant pots.
- With many colour changes, the purged filament can weigh more than the model itself.
Examples per kilo
| Weight | Per spool | Filament per piece | |
|---|---|---|---|
| Miniature (28 mm) | 3 g | ± 315 | € 0.06 |
| Keychain | 8 g | ± 118 | € 0.16 |
| 3DBenchy (test boat) | 13 g | ± 73 | € 0.26 |
| Phone stand | 40 g | ± 23 | € 0.80 |
| Plant pot | 120 g | ± 7 | € 2.40 |
| Cosplay helmet | 800 g | 1 | € 16.00 |
Based on 950 grams of usable filament and PLA at € 20 per kilo.
How to calculate it yourself
Number of prints = usable weight ÷ weight per print. Use 950 grams as usable weight for normal prints, and less if you use a lot of supports or multiple colours.
Where does the rest go?
- Supports. Prints with overhangs use 5 to 25% extra filament for support.
- Brim, skirt and purge line. A few grams per print, which adds up with many small prints.
- Colour changes. In multicolour printing the printer purges old filament at every change. With hundreds of changes that can outweigh the model.
- Failed prints. A failed print also costs filament. See what failed prints cost.
- The leftover. The last metres on a spool are sometimes too short for another print.
Getting more prints out of a spool
- Use 10 – 15% infill for decoration, and 2 – 3 walls rather than more infill for strength.
- Orient your model so it needs less support, or use tree supports.
- In multicolour prints, flush into infill or another object if your slicer supports it.
- Keep leftovers for small prints such as keychains and test prints.
Frequently asked questions
How many metres of filament are on a 1 kg spool?
For 1.75 mm PLA about 330 metres. PETG is slightly heavier, with about 325 metres per spool.
How long does a spool of filament last?
It depends on what you print. People who print a few evenings a week often get several weeks to a month out of a spool.
How do I know how much my print weighs?
Your slicer shows the weight after slicing. You can also upload an STL file in the calculator on this site for an estimate.
Calculate the cost of your print
Enter weight, print time and material and instantly see what your print costs, including electricity, wear and failed prints.
Calculate the cost of your print →