Layer Height Calculator
Not a whole number of Z steps means visible banding.
Work out Layer Height. Not a whole number of Z steps means visible banding. Every rate is an input, not an assertion.
Of nozzle diameter
50%
Within the workable band · 250 layers
A layer must be between roughly 25% and 80% of the nozzle diameter. Above that the extrusion sits on top of the previous layer rather than squashing into it and the part delaminates; below it, the nozzle drags through what it just laid down. On a leadscrew printer the layer height should be a whole number of Z steps. Anything else makes the stepper round alternate layers up and down, producing visible banding that looks like an extrusion problem and is not. Stair-stepping on a sloped surface is the layer height divided by the tangent of the wall angle. A 45° wall steps by exactly the layer height; a 20° one steps by nearly three times it, which is why shallow domes look so much rougher than steep ones.
How the Layer Height Calculator works
Checks a layer height against both constraints — the workable band of 25 to 80% of nozzle diameter, and whole Z steps on a leadscrew — with stair-stepping on sloped surfaces quantified.
Also known as: magic numbers 3d printing · best layer height for 0.4 nozzle · why is my print banded · layer height and strength
Frequently asked questions
What layer height should I use with a 0.4 mm nozzle?
Between about 0.1 and 0.32 mm. Below 25% of nozzle diameter the nozzle drags through what it laid down; above 80% the extrusion cannot squash into the layer below.
What are magic numbers in 3D printing?
Layer heights that are a whole number of Z motor steps. Anything else makes the stepper round alternate layers up and down, producing banding that looks like an extrusion fault.
Does layer height affect strength?
Yes, and not simply. Thicker layers bond better in Z because more molten material meets the layer below; thinner layers give finer detail and weaker interlayer adhesion.
Why do shallow slopes look rougher?
Stair-stepping is the layer height divided by the tangent of the wall angle. A 45° wall steps by exactly the layer height; a 20° one steps by nearly three times it.
Do belt-driven Z axes have magic numbers?
Less critically. The constraint comes from leadscrew pitch and microstepping; belt Z axes and printers with lead screws matched to their step angle are far more forgiving.
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