Filament & Resin Calculators
Filament Density Calculator
Calculate 3D printing filament density (g/cm3) from a measured sample so length, weight, and cost math match your actual spool.
Results update below from browser-local calculations.
Breakdown
| Estimated volume | 0 |
|---|---|
| Density estimate | 0 |
How to Use This Calculator
- Cut a known length of filament, or weigh a measured sample on a scale that reads to 0.01 g.
- Enter the filament diameter and the sample length or measured mass the calculator asks for.
- Use the resulting density in your slicer or in length-to-weight and cost calculations for that specific spool.
Inputs and Assumptions
| Filament length | Enter this value in m. |
|---|---|
| Filament diameter | Enter this value in mm. |
| Weight | Enter this value in g. |
Filament density example
A 1.75 mm filament sample that is 1000 mm long and weighs 3.0 g works out to roughly 1.25 g/cm3, which is typical for PLA. PETG is usually near 1.27 and ABS near 1.04.
Why Measure Density at All
Density links filament length, weight, and cost. With an accurate density you can convert a slicer's gram estimate into meters of filament, check how much is left on a spool, and price a print correctly.
Generic tables are only a starting point. Colorants, glow or wood fillers, and brand differences shift the real density, which is why measuring your own spool is more accurate.
Typical 3D Printing Filament Densities
- PLA: about 1.24-1.25 g/cm3.
- PETG: about 1.27-1.29 g/cm3.
- ABS and ASA: about 1.04-1.07 g/cm3.
- TPU: about 1.20-1.22 g/cm3, varying by shore hardness.
- Filled filaments such as wood, glow, carbon, or metal can differ significantly from these values.
How Density Is Calculated
Density = mass / volume. For round filament, volume = cross-sectional area x length, where area = pi x (diameter / 2) squared.
Because area depends on the square of the radius, a small diameter error changes the result a lot. A digital caliper and a 0.01 g scale give the most reliable reading.
Use Density in Length and Cost Math
Once you have a measured density, plug it into the length-to-weight calculator to convert grams to meters, or into filament cost math to find a true cost per gram and per meter.
Formula
Volume = π × (diameter / 2)² × length. Convert mm³ to cm³, then density = weight / volume.
Limits of This Calculator
- Diameter error has a large effect because area depends on the radius squared, so measure diameter carefully.
- Use an accurate scale and a clean, straight sample, and average several measurements for a reliable value.
- Density varies by brand, color, and fillers, so measure the actual spool instead of trusting a generic table.
FAQ
Can this identify a material?
No. Density can help compare samples, but it is not a material identification test.
Should I use several measurements?
Yes. Averaging multiple diameter and weight measurements improves the estimate.
What is the density of PLA, PETG, and ABS?
PLA is roughly 1.24-1.25 g/cm3, PETG about 1.27-1.29 g/cm3, and ABS or ASA about 1.04-1.07 g/cm3. Filled and specialty filaments can differ, so measure your own spool when accuracy matters.
Why does filament diameter matter so much?
The cross-sectional area depends on the radius squared, so a small diameter error has an outsized effect on the calculated density. Measure the diameter carefully with calipers.
Do I need to measure every spool?
For precise length, weight, and cost math it helps, because color, brand, and fillers shift density. For rough estimates a typical value for the material is usually close enough.