How Many Meters of Filament Are in A Spool?

Have you ever been the middle of a 3D printing project only to notice that the amount of filament left in your spool might be cutting it close to what your model needs? This can drive anyone anxious, as running out filament in the middle of a print might mean needing to start over.
Finding out exactly how much filament you have left in a spool may be difficult to nail accurately, but it’s not impossible to come up with a reasonable estimate. If you’ve always wanted to document the length of filament in each of your partially consumed spools, then here’s a quick guide.
Why bother finding out?
While it doesn’t take a lot of work to estimate how much leftover filament you have for each spool, many would argue that it’s not necessary. Ignorance is bliss, and one can just order another spool online if they are close to running out. However, there are two crucial moments in a 3D printing project where this information can come in handy:
While you are slicing a 3D model
One of the final steps in translating a 3D model to a language that can be understood by a 3D printer involves processing it in a slicer software. This is where you can make tweaks to the mode to optimize it for 3D printing. You can adjust the wall thickness, change the infill patterns , and add support structures if needed.
Making changes to any of these parameters means that the software will adjust how much filament is needed to print the model. Once you’re satisfied with your settings, the software will give you a final number, typically in terms of the length of filament you will need.
Now, check that number with the length of filament you have left. If you don’t have enough filament, then this is your last chance to tweak your slicer settings just so you can eke out one last print from your spool.
When you mount a spool to start 3D printing
If you don’t keep a detailed inventory of how much filament you have in each spool, then mounting any of them to your 3D printer to start a project is an exercise in guesswork at best. Do you have enough filament or are you going to run out before the project finishes?
It’s better to be sure because keeping an eye on a 3D printer for several hours is only a notch higher in the entertainment spectrum to watching paint dry.
Which information do you need?

Fortunately, there is only one tool you need to reasonably estimate the length of filament left in a spool – a digital balance. If you don’t have one yet, then this is the time to consider buying one. A digital scale should be an essential part of your 3D printing workshop. They don’t need to be expensive. This digital kitchen scale from 1 BY ONE has a capacity of 5 kilograms, comes with a stainless steel platform, and costs less than $15.
Once you have your digital scale balanced and calibrated, go ahead and weigh your spool with the leftover filament. Write this number down....