3D Print Time Calculator
Estimate how a change in printing speed may affect an existing slicer time estimate.
Original slicer estimate
Speed change
The nominal speed your slicer estimate assumed.
Estimated print time
6 h 00 min
- Original print time
- 8 h 00 min
- Original speed
- 60 mm/s
- New speed
- 80 mm/s
A proportional estimate, not a re-slice — real time won't scale perfectly because not every part of a print runs at the nominal speed.
How it's calculated
Real print time depends on geometry, acceleration, travel moves, layer changes, infill, walls, supports, and more — far too much to model from just a size and a speed. So instead of predicting time from scratch, this calculator scales a time estimate you already have (from your slicer) by the ratio between your original and new nominal print speed:
Estimated print time
Original print time × Original speed ÷ New speed
This is a simple proportional estimate, not a physics simulation. Real time won't scale perfectly with speed, because large parts of most prints — short segments, corners, small details, travel moves — are limited by acceleration and jerk/junction settings rather than your requested top speed, so they take roughly the same time regardless of the speed you set.
Assumptions
- Your inputOriginal print time, original speed, and new speed — you enter these directly, using your slicer's own time estimate as the starting point.
- Derived valueThe estimated new print time is derived exactly from those inputs using simple proportional scaling — it is not a re-simulation of your print.
- Industry approximationThis is a rough estimate, not a guarantee. Acceleration, cooling pauses, geometry, and travel moves all mean the real result will typically differ from a pure speed ratio — re-slicing at the new speed is always more accurate.
Worked example
Your slicer estimates 8 hours at a nominal print speed of 60mm/s. You want to know the rough effect of printing at 80mm/s instead.
Estimated time = 8 × 60 ÷ 80 = 6 h 00 min.
Frequently asked questions
How accurate is a 3D print time calculator?
This calculator is a simple proportional estimate, not a physics simulation — it scales an existing slicer time estimate by the ratio of old to new speed. It's most accurate for small speed changes on prints that are already mostly running at a steady nominal speed. For a genuinely accurate time estimate, re-slicing at the new speed is always better; this tool is meant for a quick "roughly how much would this save me" check.
Why doesn't doubling print speed cut print time in half?
Not every part of a print actually reaches your requested print speed. Short segments, corners, small features, and travel moves are limited by acceleration and jerk/junction settings rather than your top speed setting, so they take about the same time regardless of the speed you request. Only the portions of the print that do reach full speed benefit proportionally, which is why real time savings are usually smaller than the simple ratio suggests.
Why is my slicer's print time different from the actual print time?
Slicers estimate time from the toolpath and your speed/acceleration settings, but they can't perfectly account for everything that happens on the real printer — firmware-level motion planning differences, cooling pauses, bed leveling probing, filament changes, and other real-world delays all add time a slicer estimate may not fully capture.
Does acceleration affect print time?
Yes, significantly, especially for prints with lots of small details or direction changes. A printer needs time to accelerate up to its target speed and decelerate before a direction change — for a print full of short segments, the printer may spend more time accelerating and decelerating than actually moving at full speed, which is part of why this calculator's simple speed-ratio estimate can diverge from reality.
Can I estimate print time before slicing?
Not accurately — total time depends on the specific geometry, layer count, infill pattern and density, wall count, and support structures, which are only known once a model is sliced. This calculator is for adjusting an estimate you already have from your slicer, not for predicting time from scratch before slicing.
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