Optimal Layer Height Calculator

"Magic Numbers" are layer heights that correspond exactly to full steps of your printer's Z-axis stepper motor.

Stepper motors move in discrete steps (usually 200 per rotation). While "microstepping" allows them to stop between steps, the holding torque at these intermediate positions is weaker and less precise.

If your layer height requires the motor to hold a position at 63% of a step, gravity or vibration might cause it to settle into the nearest full step, resulting in a layer that is slightly too thick or too thin. This repeats regularly, creating visible horizontal lines known as Z-Banding.

A note on modern drivers: Many newer printers use TMC2208/2209 stepper drivers with 256× interpolation. These produce smoother motion between full steps, which makes magic numbers less critical in practice — the positional error from interpolation is only about 0.006mm. That said, full-step positions still have the highest holding torque and accuracy, so using magic numbers never hurts and can still help on printers with visible Z-banding.