# Filament and Resin Density Reference (and How to Convert Volume to Grams)

> Typical densities for PLA, PETG, ABS, ASA, TPU, nylon, PC and resin, plus the formulas for converting mesh volume to grams and a spool's weight to metres of filament.

Source: https://freestlviewer.com/blog/filament-density-reference/  
Published: August 5, 2026 · Updated: August 5, 2026

Density is the bridge between geometry and cost. A mesh gives you a volume;
density turns it into grams, and grams turn into money and print time.

## Typical densities

| Material | Density (g/cm³) |
| --- | --- |
| PLA | 1.24 |
| PETG | 1.27 |
| ABS | 1.04 |
| ASA | 1.07 |
| HIPS | 1.04 |
| TPU (95A) | 1.21 |
| Nylon (PA6/PA66) | 1.14 |
| Nylon (PA12) | 1.01 |
| Polycarbonate | 1.20 |
| Polypropylene | 0.90 |
| PVA (support) | 1.23 |
| Standard resin | 1.15 |

These are typical values for unfilled materials and are accurate enough for
estimating. For anything you are quoting a price on, use the figure from the
spool's technical datasheet — brands differ, and additives shift the number.

Composites move it a lot more than most people expect:

- **Wood-filled PLA** is usually slightly lighter than plain PLA, around
  1.15–1.25, and varies by fill percentage.
- **Glow-in-the-dark PLA** is heavier, roughly 1.25–1.30, because the
  phosphorescent pigment is a mineral.
- **Carbon-fibre filled** grades sit close to their base polymer; the fibres
  add stiffness far more than mass.
- **Metal-filled PLA** (bronze, copper, steel) commonly lands between 2.0 and
  4.0 — two to three times standard PLA. A spool holds proportionally fewer
  metres.
- **Foaming PLA** is the opposite case: its effective density depends on print
  temperature, because the foaming agent expands the extrusion. There is no
  single correct number.

## Volume to weight

```
weight (g) = volume (cm³) × density (g/cm³)
```

Mesh volume is usually reported in mm³, so divide by 1000 first. A 20 mm cube
is 8000 mm³ = 8 cm³, which is 9.9 g in PLA or 10.2 g in PETG.

That figure assumes a completely solid part. A typical FDM print is a few
perimeter walls, some solid top and bottom layers, and 10–20 % sparse infill,
so actual consumption is frequently under a third of the solid number. Treat
mesh weight as a ceiling and a comparison tool, not a prediction — the maths
and its failure modes are covered in
[volume and print weight](https://freestlviewer.com/blog/stl-volume-and-print-weight/).

## Spool weight to filament length

Filament is sold by mass but consumed by length. To convert, divide the volume
by the filament's cross-sectional area:

```
length = mass / (density × area)

area(1.75 mm) = π × 1.75² / 4 ≈ 2.405 mm²
area(2.85 mm) = π × 2.85² / 4 ≈ 6.379 mm²
```

For a 1 kg spool of 1.75 mm filament:

| Material | Approx. length |
| --- | --- |
| PLA | 335 m |
| PETG | 327 m |
| ABS | 400 m |
| TPU | 344 m |
| Nylon (PA6) | 365 m |
| Polycarbonate | 346 m |

The same 1 kg of PLA in 2.85 mm gives about 126 m, since the thicker filament
has 2.65 times the cross-section.

## Where these numbers are used

A viewer that reports estimated print weight is doing exactly the first
calculation: mesh volume in cm³ multiplied by the selected material's density,
at 100 % infill. [Mes3D](https://freestlviewer.com/) offers PLA, PETG, ABS and resin, which covers the
overwhelming majority of prints; for anything else, take the volume figure it
reports and multiply by the density from the table above.

## Frequently asked questions

### What is the density of PLA filament?

About 1.24 g/cm3 for standard unfilled PLA. PETG is around 1.27, ABS 1.04, ASA 1.07, TPU 1.21, PC 1.20 and standard photopolymer resin about 1.15. Filled and composite filaments vary widely, so check the spool datasheet when the number matters.

### How many metres of filament are on a 1 kg spool?

For 1.75 mm filament, roughly 335 m of PLA, 327 m of PETG and 400 m of ABS. The formula is length equals mass divided by density and by the filament cross-sectional area, where 1.75 mm filament has an area of about 2.405 mm2 and 2.85 mm filament about 6.379 mm2.

### How do I convert model volume to filament weight?

Multiply the volume in cubic centimetres by the material density in g/cm3. That gives the weight of a completely solid part. A real print with walls and sparse infill uses considerably less, often under a third at typical settings.

### Why is metal-filled PLA so much heavier?

Metal powder is far denser than polymer, so bronze, copper and steel filled filaments commonly land between 2 and 4 g/cm3 — two to three times standard PLA. The same model prints at the same volume but weighs proportionally more, and a 1 kg spool holds far fewer metres.