Estimate how long a print will take from the model's volume, your layer height and print speed — before you slice, and without uploading anything.
| Number of layers | — |
| Extrusion path length | — |
| Extruding time | — |
| Overhead time | — |
| Estimated total | — |
| Filament used | — |
A slicer works out print time by simulating every move. You can get within ten percent of that number with a much simpler physical model, based on one observation: the nozzle lays down a bead of plastic, and the length of that bead is fixed by how much material there is and how wide and tall the bead is.
path length (mm) = material volume (mm³) ÷ (extrusion width × layer height) extruding time = path length ÷ (print speed × efficiency ÷ 100) layers = model height ÷ layer height overhead time = layers × seconds of overhead per layer total time = extruding time + overhead time
Using the defaults above — a 45 cm³ model, 60 mm tall, 0.2 mm layers, 0.45 mm width, 60 mm/s at 70% efficiency, 2 seconds of overhead per layer — gives about 500 metres of extrusion path and roughly 3 hours 28 minutes, consuming around 56 g of PLA.
That last figure matters as much as the time, because filament grams feed straight into the print cost calculator. Time and material are the two numbers every quote depends on.
The speed you configure is a ceiling, not an average. On short moves — and most moves in a print are short — the nozzle spends a significant fraction of the distance accelerating and decelerating rather than travelling at the target rate. The faster you set the speed, the larger that fraction becomes, which is why doubling print speed typically saves far less than half the time.
The efficiency percentage accounts for this. As a rough guide: a well-tuned CoreXY holding high acceleration might average 80–90% of its set speed, while a bedslinger moving a heavy bed on Y typically averages 60–75%. If your slicer consistently predicts five hours and the printer takes seven, your real efficiency is around 70% — measure once, then reuse the figure.
Layer height appears twice in the model: it divides the number of layers, and it multiplies the bead cross-section. Halving it roughly doubles print time. That makes it by far the most powerful setting you have, and also the one with the most visible effect on the finished part.
| Layer height | Typical use | Time impact vs 0.2 mm |
|---|---|---|
| 0.08 mm | Miniatures, display pieces | About 2.5× longer |
| 0.12 mm | Detailed models, smooth curves | About 1.7× longer |
| 0.16 mm | Good all-round quality | About 1.25× longer |
| 0.20 mm | Standard; the common default | Baseline |
| 0.28 mm | Functional parts, prototypes | About 0.7× — noticeably faster |
| 0.32 mm+ | Large, simple, non-visual parts | About 0.6× — fastest |
Three reasons. The slicer's acceleration model is an approximation of your machine's real motion. Firmware features such as input shaping, pressure advance and junction deviation change the achievable speeds. And most slicers do not account for the time spent heating the bed and hotend before the first move, which is a fixed few minutes on every job.
It depends almost entirely on layer height and how much of that mass is perimeter versus infill. At 0.2 mm layers and typical settings, 100 g of PLA is roughly 80 cm³ and usually takes somewhere between four and seven hours. Use the calculator above with your actual volume for a real figure.
Speed itself is less damaging than the settings people change to get it. Higher layer height costs vertical resolution but is often invisible. Very high speeds with insufficient cooling cause poor layer adhesion and surface defects. Increase speed and cooling together, and validate with a test print before committing to a long job.
Yes — that is what this calculator is for. It needs the model volume, which most CAD tools and slicers report from the mesh itself, and your print settings. It will not be exact, but it is close enough to decide whether a job fits in an overnight window, which is usually the actual question.