Filament calculator for 3D printing
This filament calculator converts 3D printing filament between weight and length and works out the material cost of a print. A 1 kg spool of 1.75 mm PLA holds about 335.3 m of filament, because one meter weighs 2.98 g at the density of 1.24 g/cm³ given in the Prusament PLA datasheet.
Example: I know the …: weight (grams) · Material: PLA (1.24 g/cm³) · Filament diameter: 1.75 mm · Weight 1,000 g · Spool price 20 · Net weight of the spool 1,000 g → Result: 335.3 m of 1.75 mm PLA filament in 1,000 g. Source: Prusament (Prusa Polymers) – Prusament PLA: safety data sheet v3.1 of 19.08.2024 linked on this page (density 1.24 g/cm³); prusament.com: diameter tolerance ± 0.02 mm (read 09.10.2026). Updated: .
How it is calculated
Length = weight ÷ (π × (d/2)² × density). The cross-section of 1.75 mm filament is 2.405 mm², so one meter is 2.405 cm³. Multiplied by the density this gives the weight per meter – 2.98 g/m for PLA. For 2.85 mm filament the cross-section is 6.379 mm² and one meter of PLA weighs 7.91 g.
How many meters are on a 1 kg spool?
| Material | Density | 1.75 mm | 2.85 mm |
|---|---|---|---|
| PLA | 1.24 g/cm³ | 335.3 m | 126.4 m |
| PETG | 1.25 g/cm³ | 332.6 m | 125.4 m |
| ABS | 1.04 g/cm³ | 399.8 m | 150.7 m |
| ASA | 1.13 g/cm³ | 367.9 m | 138.7 m |
| TPU 95A | 1.22 g/cm³ | 340.8 m | 128.5 m |
| PC | 1.19 g/cm³ | 349.4 m | 131.7 m |
| Nylon (PA) | 1.12 g/cm³ | 371.2 m | 140.0 m |
| PLA-CF | 1.29 g/cm³ | 322.3 m | 121.5 m |
The PLA density of 1.24 g/cm³ comes from the Prusament PLA datasheet (ISO 1183). The other values are from Polymaker’s table of its own filaments (PolyLite PETG, ABS and PC, Polymaker ASA, PolyFlex TPU95, PolyMide CoPA, PLA-CF). Other brands differ: Polymaker lists its PLA types between 1.17 and 1.37 g/cm³. If you know the density of your filament, choose “Other”.
Examples
- A print of 50 g PLA: 16.8 m of 1.75 mm filament. With a 20 spool of 1000 g the material costs 1.00.
- The slicer says 10 m: that is 29.8 g of PLA.
- ABS goes further: a 1 kg spool of ABS holds 399.8 m – almost 20 % more than PLA, because ABS is lighter.
- Tolerance: Prusament gives 1.75 ± 0.02 mm. At 1.77 mm the same length weighs 2.3 % more.
The density calculator works out the density from weight and volume. For the electricity of a long print use the electricity cost calculator, and for resin casting the epoxy resin calculator.
How much is left on my spool?
Weigh the spool and subtract the weight of the empty spool (many makers print it on the label or website). Enter the rest in grams to see the remaining length, then compare it with the length the slicer needs for your print.
Frequently asked questions
How many meters of filament are on a 1 kg spool?
About 335.3 m of 1.75 mm PLA, 332.6 m of PETG and 399.8 m of ABS. With 2.85 mm filament it is 126.4 m of PLA.
How much does 1 meter of PLA filament weigh?
2.98 g at 1.75 mm and 7.91 g at 2.85 mm, calculated with a density of 1.24 g/cm³.
How do I calculate the cost of a 3D print?
Material cost = spool price × print weight ÷ spool weight. A print of 50 g from a 1000 g spool costing 20 costs 1.00 in material. Electricity, wear and failed prints come on top.
Why does the slicer show a different weight?
Slicers use the density set in the filament profile. If that differs from the real material, the weight is off by the same percentage – set the density from the datasheet.
Is the result exact?
It is an estimate. Real filament varies in diameter (Prusament: ± 0.02 mm) and density between colors and brands.
How do I convert filament length to grams?
Multiply the length in meters by the weight per meter: 10 m of 1.75 mm PLA × 2.98 g/m = 29.8 g.
Sources and legal basis
- Prusament (Prusa Polymers) – Prusament PLA: safety data sheet v3.1 of 19.08.2024 linked on this page (density 1.24 g/cm³); prusament.com: diameter tolerance ± 0.02 mm (read 09.10.2026)
- Prusa Polymers – Technical datasheet Prusament PLA, version 1.1 (density 1.24 g/cm³, ISO 1183; 1.75 ± 0.02 mm), copy hosted by MatterHackers (read 09.10.2026)
- Polymaker Wiki – Technical Data at a Glance (density of PETG, ABS, ASA, TPU, PC, nylon, PLA-CF; read 09.10.2026)
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