E-steps, Rotation Distance & Flow Calibration
Three calibrations in one place. Mark and extrude 100 mm for e-steps or rotation distance; measure a single-wall cube for flow; check whether your hotend can keep up with your speed.
How it's calculated
new e-steps = current × requested / actually extruded new rotation distance = current × actually extruded / requested new flow % = current × target wall / measured wall volumetric flow = line width × layer height × speed (mm³/s)
- E-steps (Marlin) and rotation distance (Klipper) are inverses of each other: more steps per mm means a smaller rotation distance.
- Flow calibrates the extrusion multiplier so a single wall measures what the slicer intended. Measure in several places with calipers and average.
- Volumetric flow is the ceiling: if width × height × speed exceeds what the hotend can melt, the slicer silently slows down or you under-extrude.
Questions people ask
How do I calibrate e-steps?
Mark the filament 120 mm above the extruder entry, command 100 mm of extrusion at 1–2 mm/s, then measure what is left to the mark. New e-steps = old × 100 / (120 − remaining). Save with M500.
What is a good max volumetric flow?
A stock Ender 3 hotend manages about 9 mm³/s on PLA; Prusa MK4S about 16 (22 with the high-flow nozzle); Bambu P1/X1 about 26 on PLA (Bambu rates them at 32 with ABS); high-flow hotends such as the Rapido UHF or FlowTech reach 30–35 on PLA. The hotend table on this site has the full list with sources.