3D Print Time Estimator (Layer Height, Speed & Flow)

How it works

flow (mm³/s) = layer height × line width × speed, capped at the hot-end maximum · extrusion time = plastic volume ÷ flow · print time ≈ extrusion time × (1 + overhead) + warm-up

Every second a printer is extruding it deposits a bead whose cross-section is the layer height times the line width, moving at the print speed, so volume per second is simply the product of the three — and the total volume of plastic divided by that flow is the irreducible extrusion time. Real prints take longer because the head must travel, retract, accelerate and slow down for corners and short layers, which the overhead percentage captures. The hot end imposes the hard ceiling: it can only melt so many cubic millimetres per second, so beyond that point raising the slicer speed changes nothing. That is why thick layers and wide lines speed up prints only until the melt limit is reached, and why high-flow nozzles are the real upgrade for fast machines.

Worked example

24.4 cm³ of plastic at 0.2 mm layers, 0.42 mm lines and 80 mm/s needs 6.7 mm³/s — within a 15 mm³/s hot end — so pure extrusion takes 24,400 ÷ 6.72 ≈ 3,630 s (60 min). With 35% overhead and 5 minutes of warm-up the print is about 1 h 27 min, using roughly 0.16 kWh (≈ $0.03). At 0.28 mm layers the same part takes about 1 h 3 min.

Frequently asked questions