G-code Cost Estimation: Calculate Print Time and Filament Usage

While STL files give you geometry, G-code files give you the full picture. A sliced G-code file contains the exact instructions your printer will execute — every move, every extrusion, every temperature change. That makes it the most accurate source of cost data you can get. If you're serious about precise quoting, understanding G-code metadata is a game-changer.

What G-code Metadata Contains

Modern slicers embed rich metadata in the comment lines of G-code files. This metadata typically includes:

• Estimated print time — total hours and minutes, often broken down by phase (printing, travel, retraction)
• Filament usage — length in millimetres and weight in grams
• Filament type — PLA, PETG, ABS, etc.
• Layer height and count — affects surface quality and time
• Infill percentage — directly impacts material usage
• Printer profile — which machine the file was sliced for
• Slicer software and version — Bambu Studio, OrcaSlicer, PrusaSlicer, Cura, etc.

This data is far more accurate than volume-based estimates from an STL file, because it accounts for the actual slicer settings: infill pattern, support strategy, travel moves, acceleration profiles, and more.

How G-code Parsing Works

G-code metadata is stored as comment lines, typically starting with a semicolon (;) at the beginning of the file. Each slicer uses slightly different formatting:

Bambu Studio / OrcaSlicer: Uses key-value pairs like ; total estimated time = 2h 15m and ; filament used [g] = 45.2. These slicers produce well-structured metadata that's straightforward to parse.

PrusaSlicer: Similar format with lines like ; estimated printing time = 2h 15m 30s and ; filament used [mm] = 15234.5. Note that PrusaSlicer reports filament length in millimetres — you'll need the filament diameter and density to convert to grams.

Cura: Uses a different comment style: ;TIME:8130 (seconds) and ;Filament used: 5.4321m (metres). The format varies between Cura versions, so robust parsing needs to handle multiple patterns.

From Metadata to Cost

Once you've extracted print time and filament weight, calculating cost is straightforward:

Print Cost = (Filament Weight × Price per Gram) + (Print Time × Machine Hourly Rate) + Labour + Overhead

The beauty of G-code-based estimation is that the slicer has already done the hard work of calculating exact material usage and time. You don't need to guess at infill percentages or support material — it's all baked into the numbers.

For a 45 g PETG print with a 2-hour 15-minute estimated time:

• Material: 45 g × $0.04/g = $1.80
• Machine time: 2.25 hours × $0.75/hr = $1.69
• Labour + overhead: $12.00
• Total cost: $15.49

Automated G-code Parsing with Printforge

Manually opening G-code files and searching for metadata is slow and tedious. Printforge includes a built-in G-code parser that automatically extracts print time, filament usage, material type, and slicer information from uploaded G-code files. It supports all major slicers — Bambu Studio, OrcaSlicer, PrusaSlicer, and Cura — and feeds the extracted data directly into the cost calculator.

Simply upload your G-code file and Printforge populates the print time and material weight fields automatically. Combined with your saved material costs and machine rates, you get an accurate quote in seconds rather than minutes.

G-code vs STL: When to Use Each

Use STL-based estimation when you receive a model from a customer and haven't sliced it yet — it gives you a fast ballpark figure for quoting. Use G-code-based estimation when you've sliced the job and want precise numbers for your final quote or internal costing. Many operators quote from STL initially, then verify against G-code before committing to the job.

Visit the Learning Centre for more guides on optimising your 3D printing workflow, or try Printforge's calculator to see automated G-code parsing in action.