Print Time Estimator Calculator
A printer deposits plastic at a volumetric rate equal to the print speed multiplied by the extruded line cross-section, which is the line width times the layer height. Dividing the total extruded volume by that flow rate gives the bare printing time. Real prints take longer because of travel moves, acceleration, retractions, and slower outer walls, so this calculator applies an overhead factor you can tune. Enter the extruded volume, print speed, line width, layer height, and overhead, and it returns the estimated print time in hours and minutes. Your slicer remains the most accurate source because it simulates the full toolpath.
Print time formula
Flow (mm3/s) = speed * line width * layer height
Bare time (s) = extruded volume / flow
Estimated time (s) = bare time * overhead factor
Hours = estimated time / 3600
The flow rate is the deposition rate at the set speed. The overhead factor scales up the bare time to allow for travel, acceleration, and retraction, which the slicer models exactly.
Print time context
- This is a flow-based lower bound; real time is longer due to motion overhead.
- Tune the overhead factor against your own completed prints for accuracy.
- Use a representative average print speed if walls and infill differ.
- Extruded volume is the plastic deposited, not the model bounding box.
- The slicer simulates the full toolpath and remains the most precise estimate.
Print time estimate: frequently asked questions
How can I estimate print time from volume?
Printing lays down plastic at a volumetric rate equal to the print speed times the line width times the layer height. Dividing the total extruded volume by that flow rate gives the printing time. Convert seconds to hours by dividing by 3,600.
Why is this only an estimate?
It assumes the nozzle moves at the set print speed the whole time, but real prints include travel moves, acceleration and deceleration, retractions, and slower outer-wall speeds. Those make the real time longer, so treat the result as a lower bound and use a multiplier to allow for overhead.
What print speed should I enter?
Use your slicer's main print speed in millimeters per second. If you use different speeds for walls and infill, enter a representative average. Higher speeds shorten the estimate proportionally.
Where does extruded volume come from?
Your slicer reports the filament volume used, or you can compute it from the print weight divided by the material density. The volume here is the plastic actually deposited, not the bounding-box volume of the model.
How do I add realistic overhead?
Multiply the flow-based estimate by an overhead factor greater than one to account for travel and acceleration. A factor you calibrate against a few of your own completed prints will make future estimates more reliable.
Official sources
- RepRap project documentation: reprap.org (extrusion and slicing reference).
- Marlin firmware documentation: Configuration reference.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.