Filament Density & Weight Calculator
Convert between filament weight, length, and density. Includes material presets for PLA, PETG, ABS, ASA, and TPU in standard diameters.
Last updated: May 2026
Select filament diameter and material to calculate weight-to-length conversion.
Why understand filament density
Different materials have different densities. A 1 kg spool of PLA (1.24 g/cm³) holds ~333 meters of 1.75mm filament. The same weight of ABS (1.04 g/cm³) holds ~400 meters. Understanding material density lets you compare filament value, estimate remaining spool weight, and predict print costs accurately.
Knowing weight-per-meter is also critical for remote weight sensors (scales under your printer) and for debugging print failures related to filament variation.
Material density reference table
| Material | Density (g/cm³) | Length per kg (1.75mm) | Length per kg (2.85mm) | Notes |
|---|---|---|---|---|
| PLA | 1.24 | 333 m | 115 m | Most popular, consistent, low shrinkage |
| PETG | 1.27 | 325 m | 112 m | Stronger than PLA, better layer adhesion |
| ABS | 1.04 | 397 m | 137 m | Stronger, prone to warping, needs enclosure |
| ASA | 1.07 | 385 m | 133 m | ABS alternative, better UV resistance |
| TPU | 1.21 | 346 m | 119 m | Flexible, slower print speed, more retractions |
| Nylon | 1.14 | 368 m | 127 m | Very strong, requires high temp and dry storage |
Common spool sizes and material estimates
| Spool Size | PLA Weight (g) | PETG Weight (g) | ABS Weight (g) | Typical Length (1.75mm) |
|---|---|---|---|---|
| 250g spool | 250 | 250 | 250 | 80–100 m |
| 500g spool | 500 | 500 | 500 | 160–200 m |
| 1kg spool | 1000 | 1000 | 1000 | 330–400 m |
| 2kg spool | 2000 | 2000 | 2000 | 660–800 m |
Practical usage examples
Estimating remaining filament
Your spool feels light. You know you started with 1kg of PLA (1.75mm). Weigh it: 350g remaining. Using the calculator: 350g ÷ 3.33 g/meter = ~105 meters left. Enough for a small print or Benchy, but not a helmet.
Comparing material value
Filament A: $18 for 1kg PLA (1.24 g/cm³). Filament B: $25 for 1kg Nylon (1.14 g/cm³). Nylon gives 368m/kg vs PLA's 333m/kg. Cost per meter: A = $0.054/m, B = $0.068/m. PLA is better value, but Nylon is only 25% more expensive for much greater strength.
Optimizing for weight sensors
If your printer has a filament weight sensor, you need to know the grams-per-meter to calibrate the sensor. For 1.75mm PLA, enter the values: sensor reads 100g remaining = ~30 meters = enough for ~20 minutes at 60mm/s.
FAQ
Why do different PLA brands have slightly different densities?
Manufacturing variations, additives (color pigments, flame retardants), and moisture content cause density to vary by ±0.02 g/cm³. Use 1.24 as a standard for PLA, but weigh-and-measure your own filament if precision matters for your application.
How do I measure filament density myself?
Weigh a precise length of filament (e.g., 1 meter) using a precision scale (±0.01g). Divide the weight by the volume. For 1.75mm diameter: volume = π × (0.0875cm)² × length(cm) = 0.024 cm³/cm. Density = weight(g) ÷ volume(cm³).
Does humidity affect filament density?
Not significantly. Moisture absorption can add 0.1–0.5% weight to hygroscopic materials (Nylon, ASA), but this is negligible for cost calculations. For critical applications, store filament in dry boxes and re-measure if humidity has been high.
Which filament is lightest (lowest density)?
ABS at 1.04 g/cm³. This means 1kg of ABS yields ~400 meters of 1.75mm filament, the most length for the weight. However, ABS is harder to print reliably and prone to warping.
Why is TPU different from rigid plastics?
TPU is flexible and has slightly lower density (1.21 vs 1.24 for PLA). This affects extrusion pressure and print speed. TPU prints best at 30–50 mm/s, slower than PLA, because the flexible material doesn't push through the nozzle as efficiently.
How accurate is the weight-per-meter calculation?
Accurate to ±3% for standard commercial filament. Variations in filament diameter tolerance (should be ±0.05mm but sometimes ±0.1mm) and density variation cause the remainder. If absolute precision is needed, weigh a measured length of your actual filament.