3D Print Time Estimator
Ballpark how long a print will take from filament weight and printer class. This is a rough guide. Your slicer is always the authoritative source, but sometimes you just want a number before you slice.
How this works
Different printers extrude filament at different rates. A fast CoreXY like the Bambu X1C averages around 30 grams per hour at typical settings. An older Ender 3 at stock speeds is closer to 10 g/hr. Divide your filament weight by throughput and you get a rough hours-to-print estimate.
Why this is rough: throughput depends on layer height, infill, speed profiles, and whether your print has a lot of small detail or long flat walls. Slicers simulate every move and can tell you the actual expected time for a specific file. Use them for precise answers.
The formula in detail
The math is straightforward:
hours = grams / throughput_g_per_hr
Worked example. A vase that uses 240 grams of PLA on a Bambu P1S (typical throughput 28 g/hr): 240 / 28 = 8.57 hours, or roughly 8 hours 35 minutes. The same vase on an Ender 3 V2 at stock speeds (10 g/hr): 24 hours. Same file, same filament, two and a half times longer because the printer is slower.
The throughput numbers in this calculator come from community-aggregated data: print logs people post on Reddit, Bambu forums, and Klipper Discord. They represent typical real-world settings, not advertised maximums. Your specific machine can run slower (poor cooling, fine detail, slow profile) or faster (Klipper input shaping, lightweight toolhead, aggressive acceleration).
Throughput by printer class
Reference numbers for the most common printer tiers, at default settings on PLA. Adjust down for tougher materials or fine detail.
| Printer class | Typical g/hr | Notes |
|---|---|---|
| Ender 3 (stock) | 8 to 12 | Bowden, slow accel, conservative speeds |
| Ender 3 V3 KE | 15 to 20 | Klipper-based, faster than original |
| Prusa MK4 | 20 to 28 | Quality first, speed second |
| Bambu A1 / A1 mini | 22 to 30 | Bedslinger but tuned for speed |
| Bambu P1S | 25 to 32 | CoreXY, balanced quality and speed |
| Bambu X1 Carbon | 28 to 36 | CoreXY, fast on PLA, slows down on engineering filaments |
| Voron 2.4 (tuned) | 35 to 50 | Klipper, light toolhead, input shaping |
| Resin printer (rough comparison) | N/A | Time depends on print height, not weight |
What slows your print down
Knowing why prints take longer than the slicer estimate helps you plan around it. The big factors:
- Layer height. Halving layer height roughly doubles print time. A part at 0.16mm layers takes about 1.5x longer than the same part at 0.24mm.
- Infill density and pattern. Going from 15% to 50% infill on the same part can add 30 to 50% print time. Gyroid is faster than honeycomb at the same density.
- Wall count. Each extra perimeter adds outer-loop time at the slowest speed. Walls are usually printed slower than infill for surface quality.
- Supports and tree supports. Tree supports use less filament than grid but often take more time to print because of all the small features.
- Travel distances. Lots of small islands across the bed means more travel time, even if total filament stays the same.
- Cooling. Small layers (small parts at high detail) need cooling time. Your slicer adds minimum layer time to keep the part from melting.
Three quick examples
Quick 3DBenchy
- 20 g of PLA on a Bambu A1 (26 g/hr typical)
- Math: 20 / 26 = 0.77 hours, about 46 minutes
- Reality: closer to 30 minutes on standard speed profile (small parts run faster than weight suggests)
Mid-size cosplay piece
- 180 g of PLA on a Bambu P1S (28 g/hr typical)
- Math: 180 / 28 = 6.4 hours
- Reality: close to estimate if printed at standard quality
Articulated dragon (heavy supports)
- 320 g of PLA on a Bambu P1S
- Math: 320 / 28 = 11.4 hours
- Reality: 13 to 15 hours because of tree supports and small joint detail
The estimator is closest to truth for medium prints with normal settings. Very small prints finish faster (less material per layer but layer count is what dominates time). Very detailed prints with heavy supports take longer.
When to trust this estimate vs the slicer
- Use this calculator when you don't have a sliced file yet. Browsing Printables and wondering if a 250 g model fits in your evening? Two-second answer.
- Use your slicer when you're about to commit to the print. The slicer simulates every move at your actual speeds and gives a number that's usually within 5 to 10% of real time.
- Trust neither for prints that are mostly supports, mostly small detail, or use non-standard speed profiles. Add 30% to whichever number you got.
Frequently asked
- How accurate is this compared to a slicer?
- Not as accurate. Slicers simulate every move at the actual speeds you've configured, so they're the authoritative source. This calculator gives a rough hours-to-print estimate from weight, useful before you've sliced a file or when you just want to know if a print will finish before bed.
- What does 'throughput' mean?
- Grams of filament your printer extrudes per hour during normal printing. A Bambu X1C averages around 30 g/hr. An Ender 3 at stock settings is closer to 10 g/hr. Klipper-tuned fast builds can push 40+ g/hr.
- Why is my print so much slower than this estimate?
- Throughput varies hugely with print settings. Fine detail at 0.1mm layers with 80% infill can halve the throughput. Sparse gyroid infill with 0.28mm layers speeds it up. Supports add time without adding much filament. Travel moves also cost time. Check your slicer.
- Is this throughput number the same as volumetric flow?
- Close but not identical. Volumetric flow (mm³/s) is what limits your printer at the hotend. Throughput in g/hr already accounts for filament density and typical infill patterns. For most users, g/hr is the more practical number.
- Do multi-color prints take longer?
- Yes, significantly. Bambu AMS color swaps add 30 to 90 seconds each plus purge filament. A print with 50 color swaps adds roughly 30 to 75 minutes on top of the base time this calculator estimates. The dedicated AMS calculator ships in a later update.