How to Use G-code to Auto-fill Print Weight & Time in Your Calculator
Every G-code file contains the exact filament weight and estimated print time embedded as comments by your slicer. Once you know where to find them — or use a calculator that reads them automatically — you never have to estimate again.
Slicer Support at a Glance
| Slicer | Embeds weight? | Embeds time? | Weight unit | Auto-fill works? |
|---|---|---|---|---|
| PrusaSlicer | ✅ | ✅ | grams | ✅ |
| OrcaSlicer | ✅ | ✅ | grams | ✅ |
| Bambu Studio | ✅ | ✅ | grams | ✅ |
| Ultimaker Cura | ✅ | ✅ | metres* | ✅ (auto-converted) |
| SuperSlicer | ✅ | ✅ | grams | ✅ |
| IdeaMaker | ✅ | ✅ | grams | ✅ |
*Cura exports length in metres, not grams. The calculator converts automatically using filament density.
Where to Find Weight & Time in Each Slicer
PrusaSlicer & SuperSlicer
After slicing: summary panel bottom-left shows "Used filament" and "Estimated printing time". In the G-code file: look for ;filament used [g] = 12.34 and ;estimated printing time (normal mode) = 1h 23m. To ensure embedding: Print Settings → Output Options → enable "Verbose G-code" mode.
OrcaSlicer
After slicing: top summary bar shows weight (g) and time per plate. G-code header includes ;filament used [g] and ;estimated printing time. OrcaSlicer 2.3+: per-filament weight breakdown for multi-material prints.
Bambu Studio
Prepare tab → Slice → summary panel shows per-plate and total weight + time. Exported .gcode/.3mf embeds same ;filament used [g] format (shared codebase with OrcaSlicer). Also works with .bgcode (binary G-code format) in Bambu-native export.
Ultimaker Cura
Bottom-right panel shows "Time" and filament length/weight after slicing. G-code embeds ;Filament used: 3.12m (metres, not grams). Conversion for 1.75mm PLA: metres × 2.49 ≈ grams (varies by material density).
Cura exports filament length in metres, not grams. For 1.75mm PLA: multiply metres × 2.49 to get approximate grams. The calculator handles this conversion automatically when you drop in the file.
Step-by-Step: Using G-code Import in the Calculator
- Slice your model in your slicer as normal — any settings, any quality.
- Export or save the G-code file. Extensions: .gcode, .gco, .gcodes, .bgcode, or .txt all work.
- Open the 3D Print Calculator or Pro Calculator.
- Option A: Drag and drop the G-code file onto the G-code dropzone in the Print Setup section.
- Option B: Click "Browse" next to the dropzone and select the file from your computer.
- Weight and print time fields auto-fill — check they match your slicer's summary panel.
- Adjust material price per gram if needed, then calculate your cost.
The G-code file is read entirely in your browser — no upload, no server, no privacy concern. The file never leaves your device.
What If Auto-fill Gives Wrong or Zero Values?
| Symptom | Likely cause | Fix |
|---|---|---|
| Weight shows 0g | Slicer didn't embed metadata | Enable "Verbose G-code" or equivalent in slicer export settings |
| Time shows 0 | Time comment format not recognised | Enter manually from slicer summary panel |
| Weight seems wrong | Multi-material: total vs per-filament | Check slicer is showing combined weight, not one material |
| File rejected | Wrong extension | Rename to .gcode if needed; or use .txt as fallback |
| Cura weight wrong | Metres used, not grams | Calculator converts automatically; if wrong material, update material type |
Why Accurate Weight Matters More Than You Think
Estimating weight by eye is typically 20–40% off. A 10g underestimate on PETG (£0.032/g) = £0.32 lost per print. At 200 prints/month: £64/month in untracked costs — over £750/year. Print time affects electricity cost: a 30-minute underestimate on a 200W machine at UK rates = £0.034 per print × 200 prints = £6.80/month lost. Combined effect: consistent time + weight underestimates = systematic underpricing that compounds. See our filament cost per gram guide.
The Pro calculator's inventory tracking links G-code weight directly to your filament spool — deducting usage automatically when you save a calculation.
FAQ
Does PrusaSlicer show filament weight in grams?
Yes — in the summary panel and embedded as ;filament used [g] = X.XX in the G-code file.
Why does Cura show metres instead of grams?
Cura reports filament length. Multiply by ~2.49 for 1.75mm PLA to get grams. The calculator does this automatically.
Can I use G-code from Bambu Studio?
Yes. Both .gcode and .bgcode exports from Bambu Studio embed weight and time in the same format as OrcaSlicer.
What if my slicer isn't supported?
Any slicer that embeds ;filament used [g] or ;estimated printing time comments in standard G-code format will work. If auto-fill fails, enter weight and time manually — they're always visible in the slicer summary panel.
Try It — Drop Your G-code File
Drag and drop any .gcode file from PrusaSlicer, OrcaSlicer, Cura, or Bambu Studio. Weight and print time fill in automatically.
Open Calculator →