Print Time Estimator
Why Slicer Estimates and Reality Diverge
A slicer's time estimate accounts for travel moves, retractions, and acceleration curves that a simple formula can't see, which is why actual print times often run longer than the slicer preview promises. This calculator uses a simplified volumetric flow model — useful for a fast planning estimate before you've sliced a file, or for sanity-checking a slicer's number — based on how quickly the nozzle can lay down material at a given layer height and speed.
The Formula
Print Time = Model Volume / Flow Rate
Total Time = Print Time + Setup Time
Flow rate approximates the cross-sectional area of the extruded line (nozzle diameter × layer height) multiplied by the speed the print head travels while extruding. Setup time covers bed leveling, heating, and any prep before the first layer starts.
Where This Calculation Matters
- Scheduling print jobs — estimating duration before slicing helps decide whether a print can finish overnight or needs to start first thing in the morning.
- Comparing speed settings — before committing to a slower, higher-quality profile, this shows the time tradeoff against a faster draft setting.
- Farm capacity planning — print farms estimating throughput need a rough per-job time to plan machine allocation across a queue.
- Quoting turnaround — combined with cost, an accurate time estimate lets a service bureau quote realistic delivery dates.
Print Speed vs. Time (50 cm³ model, 0.4mm nozzle, 0.2mm layers)
| Print speed | Flow rate | Print time |
|---|---|---|
| 30 mm/s | 2.4 mm³/s | 5.79 h |
| 50 mm/s | 4.0 mm³/s | 3.47 h |
| 80 mm/s | 6.4 mm³/s | 2.17 h |
| 100 mm/s | 8.0 mm³/s | 1.74 h |
| 150 mm/s | 12.0 mm³/s | 1.16 h |
Excludes setup time and travel moves, so treat this as a lower-bound estimate rather than an exact prediction.
How to Use This Calculator
- Enter the model volume in cm³ (from your slicer or the STL Volume Calculator).
- Enter the layer height in millimeters.
- Enter the nozzle diameter in millimeters.
- Enter the print speed in mm/s.
- Optionally add setup or prep time in minutes.
- Select Calculate to get the estimated total print time.
Related Calculations
Get the model volume first from the STL Volume Calculator, then feed print hours into the 3D Print Cost Calculator.