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Filament weight calculator — volume and infill to grams

Enter model volume in cm³, infill percent, material density, and optionally filament diameter. Get an FDM shopping estimate in grams and approximate meters — not a slicer replacement.

Slicers report volume in cm³ — keep metric inputs. Results also show oz / ft.

Results

Filament grams: 12.4 g (≈ 0.44 oz)

Approx. length (m): 4.16 m (≈ 13.6 ft)

Formula

grams=volume×density×infill; meters from cross-section if diameter set

How the numbers are calculated

  1. Filament grams = 50 × 1.24 × 0.2 = 12.4 g

Rough FDM shopping estimate — trust your slicer for supports, walls, and brims.

Buying a spool without a gram estimate is a guess — especially when infill jumps from a draft 15% to a solid functional part. A quick volume×density×infill pass tells you whether a 1 kg spool covers the weekend batch.

Density is editable because PETG, ABS, and filled filaments are not PLA. Diameter unlocks a rough length from cross-section area; leave it blank if you only care about grams on the scale.

Treat the result as a shopping and quoting aid. For anything with supports or thick walls, the slicer’s material estimate still wins. When the print is for sale, move grams into pricing tools rather than inventing a per-hour guess alone.

How to use

  1. Enter volume (cm³) and infill %
  2. Set density (PLA often ≈ 1.24)
  3. Optionally set diameter to see approximate meters

Why this calculator

  • Respects infill instead of assuming solid plastic
  • Lets you edit density for different materials
  • Optional meters when you think in spool length

Good for

  • Spool shopping
  • Quote drafts
  • Infill what-if checks

Tips

  • Add a buffer for supports, brims, and failed first layers.
  • Trust the slicer report for paid client jobs.
  • Re-check density when you switch brands or filled filaments.

Examples

Input Output Note
50 cm³, 20% infill, density 1.24, 1.75 mm 12.4 g (meters shown when diameter is set) PLA density ≈ 1.24 g/cm³ is a common starting point
Same volume at 100% infill About 5× the grams of the 20% case Use this to price solid vs light prototypes before you slice

Filament FAQ

Where do I get model volume?
Most slicers show volume; for rough shopping you can estimate from a bounding box knowing it will be high.
Why is this lower than the slicer?
Supports, walls, brims, and purge are outside a pure volume×infill×density model. Add a buffer or trust the slicer for final jobs.
Pricing prints for sale?
Fold grams (plus failure buffer) into Craft pricing, then check Etsy fees if you sell online.
Resin instead of FDM?
Use Resin calculator for vat volume — different workflow entirely.

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