Layer Height Advisor

Every detail level is defined as a percentage of the nozzle diameter (75% for draft down to 25% for ultra-fine), so nozzle diameter acts as a scaling factor underneath all four detail levels. Across their full ranges, switching between the smallest and largest nozzle spans a wider range of resulting layer heights than switching between detail levels at one fixed nozzle size, though the two converge closely at the ultra-fine setting.

Layers printed too thick relative to the nozzle risk poor extrusion, because the nozzle's flat face can't press and fuse a bead that tall against the layer beneath it cleanly. This typically shows up as weak interlayer adhesion or a rough, under-extruded surface rather than a clean print.

Roughly, yes, for the same object height -- halving layer height roughly doubles the number of layers needed, and since each layer takes a similar amount of time to print, total print time scales close to proportionally. This calculator's speed comparison and 50 mm layer-count figures both illustrate that tradeoff directly.

Many desktop 3D printers use stepper motors on the Z axis with a fixed physical step resolution, and 0.04 mm is a common increment those motors can hit reliably. Snapping the raw percentage-based recommendation to that grid keeps the suggested value achievable on typical hardware rather than a theoretical number the printer can't actually produce.