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The 3D Print Time Estimator predicts FDM (Fused Deposition Modeling) print duration from model volume, layer height, infill percentage, and print speed — the four parameters slicers (Cura, PrusaSlicer, OrcaSlicer, Bambu Studio) use to schedule prints. Real-world print time depends on extrusion volumetric rate (mm³/s) governed by hotend capacity and nozzle diameter, plus overhead for travel moves, retractions, infill pattern changes, and slow-down on small features. This calculator provides a baseline ±20% estimate before slicing — useful for ordering filament, scheduling work, or comparing settings. Key relationships: layer height controls vertical resolution and stacks (0.2mm is standard, 0.12mm slow but detailed, 0.28mm fast but rough). Print speed (40–250 mm/s depending on printer class) is the linear speed of the nozzle. Infill % is the internal pattern density (15–25% typical, 80%+ for structural parts). Volume comes from the model itself (CAD report or slicer estimate). Formula approximates time = volume / (speed × layer × nozzle_width × 60) × 60, then adjusts for infill ratio. Why estimates vary from actual: every printer has different acceleration limits (Bambu X1C can hit 200+ mm/s, Ender 3 stable at 60 mm/s), every model has different geometric complexity (flat tops print faster than curved surfaces), supports add 20–40% overhead, and first layers print slower. Hotend volumetric capacity matters most for fast printers: a 0.4mm nozzle at 60 mm/s with 0.2mm layer = 4.8 mm³/s, which is at the edge of most stock hotends. Print speed beyond volumetric limit causes under-extrusion regardless of motor speed. Users: maker hobbyists planning overnight prints, print farm operators batching jobs, Etsy sellers pricing custom orders, students hitting deadline submissions, engineers iterating on prototypes. The estimate helps decide whether to print at higher quality (slow but better) vs draft mode (fast iteration). For commercial use, factor in machine hour cost ($0.50–2.00/hr depending on printer wear, electricity, maintenance) — a 12-hour print isn't free machine time.
- 1Step 1 — Get model volume from CAD report (Fusion 360, OnShape) or slicer estimate after slicing
- 2Step 2 — Enter your preferred layer height (0.2mm standard balance of speed and quality)
- 3Step 3 — Enter print speed your printer can sustain (check printer spec or recent prints)
- 4Step 4 — Enter infill percentage (15–25% typical, higher for structural parts)
- 5Step 5 — Calculator approximates effective volume = V × (0.3 + 0.7 × infill) accounting for hollow interior
- 6Step 6 — Computes time = effective volume / extrusion rate, plus overhead for travel/retracts
- 7Step 7 — Output ±20% — actual time depends on printer-specific factors; final answer comes from slicer
Effective volume after infill = 22 cm³. At 4.8 mm³/s effective extrusion, ~76 min pure print time; with overhead ~7 hours actual.
3.5× faster than standard with modern fast printer
Larger layers + higher speed + lower infill — Bambu X1C-class machines reduce same print to ~2 hours with comparable quality on most surfaces.
Tiny model but extreme detail settings — thin layers and slow speed dominate. Common for resin-printable miniatures done on FDM with limitations.
Overnight print scheduling
Print farm capacity planning
Etsy / custom order pricing
Maker class project planning
Prototyping iteration cycle planning
Filament inventory management
Why does my actual print time differ from this estimate?
Many factors: model geometry complexity (curves slow vs flat surfaces), supports (add 20–40% overhead), first layer typically prints at 20–30 mm/s regardless of setting, infill pattern type (gyroid is slower than cubic), small features force speed reduction, retraction overhead on multi-part plates. Always re-check after slicing — the slicer's estimate is more accurate.
What's the fastest setting without ruining quality?
Layer height 0.28mm + speed 100–150 mm/s on a competent printer (Prusa MK4, Bambu, Voron) is often the sweet spot. Visible layer lines but acceptable for functional parts. Resin-quality requires 0.05–0.12mm layers regardless of printer.
Does layer height affect strength?
Modestly. Thinner layers bond slightly less reliably (more interfaces); thicker layers can have weaker individual layers. The Z-direction is always the weakest axis regardless. Orient critical loads in X-Y plane when possible. For most parts the difference is small enough to choose layer height by visual quality, not strength.
How does infill density affect time?
Significantly. 20% → 50% roughly doubles print time. 50% → 100% adds another 80–100%. Most prints don't need over 25%; structural parts use 40–80% with thicker walls. Walls and tops contribute more to strength than infill — increase wall thickness (perimeters) before infill %.
What about supports?
Supports typically add 20–40% to print time and waste filament. Modern slicers (PrusaSlicer organic tree supports, Cura tree) reduce both. Better strategy is orientation optimization — rotate the model to minimize overhangs above 45°. Some parts split into pieces and glued together print faster than supported.
Pro Tip
Use slicer's preview after slicing for accurate time — this calculator gives pre-slice ballpark. For repeat prints, log actual vs estimate to calibrate your printer's overhead factor. Most printers fall in 1.0–1.4× this calculator's estimate.
References
Read the full guide on how to use this calculator effectively
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