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Max volumetric speed calculator
Read your max volumetric speed off OrcaSlicer's test print, then see what print speed it allows.
Free tool · no signup
What max volumetric speed means
It is how much filament your hotend can melt each second, in cubic millimeters. Past it, the nozzle cannot keep up and you get under-extrusion or weak layers.
It depends on the filament, the nozzle and the hotend, so each filament needs its own value. The brand and even the color of the same material can change it, according to OrcaSlicer's calibration guide.
The formulas
From the test: max volumetric speed = start value + height where it fails × step. With the defaults of 5 mm³/s and a 0.5 step, a print that fails at 19 mm gives 5 + 19 × 0.5 = 14.5 mm³/s.
Flow at your settings = layer height × line width × print speed.
Fastest speed = max volumetric speed ÷ (layer height × line width).
Common questions
Slicers such as OrcaSlicer cap each move at the filament's max volumetric speed. If layer height × line width × speed is above it, the slicer slows the move down.
OrcaSlicer's guide recommends raising the nozzle temperature toward the top of the filament's range before you push speed or flow higher.
No. Flow rate, or flow ratio, sets how much plastic each line gets. Max volumetric speed is how fast the hotend can melt it.