Filament Weight to Length Calculator
Calculate how much filament length you have from the remaining spool weight. Supports PLA, PETG, TPU, ABS and ASA in both 1.75mm and 2.85mm diameters.
Last updated: May 2026
Enter weight to calculate filament length.
How to use this filament calculator
Weigh your remaining filament (without the spool), select the material type and diameter, and see how many meters you have left. The quick buttons cover common partial spool weights. Know if you have enough to finish that 18-hour print without running out halfway.
Material density reference
| Material | Density (g/cm³) | 250g = meters (1.75mm) | 500g = meters (1.75mm) |
|---|---|---|---|
| PLA | 1.24 | ~82 m | ~164 m |
| PETG | 1.27 | ~80 m | ~160 m |
| TPU | 1.21 | ~84 m | ~168 m |
| ABS | 1.04 | ~98 m | ~196 m |
| ASA | 1.07 | ~95 m | ~190 m |
When you need this tool
Your Bambu Lab slicer says the print needs 78 meters but you don't know if your partial spool has enough. Or you're planning a multi-color print and need to verify each color has sufficient length. Or you bought a refill spool that doesn't list the remaining length. Weigh it, enter the weight here, and know exactly how much filament you have before starting that long print.
Frequently Asked Questions
Why doesn't a 1 kg spool contain exactly 1 kg of usable filament?
The "1 kg" on a spool label refers to the filament only, not the spool itself. A typical empty spool weighs 150-250 g depending on brand. Bambu Lab spools weigh ~250 g; Prusa spools weigh ~202 g; generic spools vary. Weigh your full spool and subtract the known empty spool weight to get the actual filament weight. This calculator uses only the filament weight.
How accurate is the length estimate?
Within 3-5% for standard commercial filament. The two main sources of error are filament diameter tolerance (should be ±0.05 mm but sometimes ±0.1 mm between spools) and density variation between batches. Use the result as a planning estimate. If you need to know whether you'll have just enough for a long print, add a 5% safety margin.
Does this work for 2.85 mm filament?
Yes, select 2.85 mm from the diameter dropdown. A 250 g spool of PLA at 2.85 mm has roughly 29 meters, compared to 82 meters at 1.75 mm. The same weight gives much less length because the cross-sectional area is about 2.7× larger. If your printer uses 2.85 mm (common on Ultimaker and some E3D systems), always select the correct diameter or the estimate will be significantly off.
My slicer shows grams but I need to compare it to the meters I have left, how?
Run the calculation in reverse: weigh your remaining filament (without spool), enter the weight here, and get the length in meters. Then check your slicer's length estimate (most slicers can show both grams and meters). If you have more meters available than the print requires, you're safe to start. If it's close, add a safety margin of 10-15% to account for purging and failed layers.
ABS weighs less per meter than PLA, does that mean ABS spools have more filament?
Yes. ABS has a lower density (1.04 g/cm³ vs 1.24 g/cm³ for PLA), so 1 kg of ABS at 1.75 mm gives roughly 400 meters, compared to 336 meters for PLA. This is useful when comparing value between materials, a 1 kg ABS spool gives significantly more print length than 1 kg of PETG (1.27 g/cm³), which yields about 328 meters.