Filament Weight Calculator
Turning a Spool Number Into a Print Weight
Slicers estimate filament usage from the sliced model, but when you're planning a print before slicing — or checking a slicer's estimate against a hand calculation — you need the relationship between filament length, diameter, and material density. Filament is manufactured to a tight diameter tolerance, so its volume per meter is predictable, and multiplying by density gives an accurate weight.
The Formula
Weight = Volume × Density
Diameter is entered in millimeters and length in meters; the calculator converts both to centimeters internally so the result comes out directly in grams.
Where This Calculation Matters
- Estimating remaining spool life — knowing how much a known length of filament weighs lets you back-calculate how much is left on a partially used spool.
- Cross-checking a slicer estimate — if a slicer reports filament length used, this converts it to a weight to compare against your scale.
- Shipping and inventory — makers shipping printed parts or filament need accurate weights for postage calculations.
- Material substitution — switching filament brands changes density slightly, which changes weight-per-meter even at the same diameter.
Weight per Meter by Material (1.75mm filament)
| Material | Density (g/cm³) | Weight per meter |
|---|---|---|
| PLA | 1.24 g/cm³ | 2.98 g |
| ABS | 1.04 g/cm³ | 2.50 g |
| PETG | 1.27 g/cm³ | 3.06 g |
| Nylon | 1.21 g/cm³ | 2.91 g |
| TPU | 1.21 g/cm³ | 2.91 g |
All figures assume 1.75mm diameter filament with a cross-sectional area of 2.405 mm² per meter of length (0.02405 cm³ volume per cm of length).
How to Use This Calculator
- Enter the filament length in meters.
- Enter the filament diameter in millimeters (typically 1.75mm).
- Select a material from the density dropdown, or choose Custom Density to enter your own value.
- Select Calculate to get the weight in grams and kilograms.
Related Calculations
Run the reverse calculation with the Filament Length Calculator, or feed the resulting weight into the 3D Print Cost Calculator.