3DPrintCalcs
Z-Offset Calculator — First Layer Adjustment
Calculate fine Z-offset adjustments for perfect first layer squish.
How We Calculate This
How It Works
- Ideal first layer height = Layer height x Squish factor (default 0.8 = 20% squish; 0.75 gives 25%, 0.90 gives 10%)
- Squish percentage = (Layer height - Ideal) / Layer height x 100
- Adjustment = Based on observed issue — too high gives a negative Z step (nozzle closer), too low gives a positive step (nozzle further away)
- New offset = Current offset + Adjustment
- Layer-height check = compares your layer height against 25%–80% of the nozzle diameter (the usable FDM band)
The ideal first layer is slightly compressed compared to subsequent layers. This extra squish ensures the filament is pressed firmly into the bed surface for good adhesion. A negative Z offset moves the nozzle closer to the bed; a positive Z offset moves it away. Adjust in small 0.02–0.05 mm steps (baby stepping) and watch the first layer.
Frequently Asked Questions
Z offset is a fine adjustment to the distance between the nozzle and the bed. Negative values bring the nozzle closer, positive values move it further away. It compensates for mechanical tolerances.
The first layer should be slightly squished — lines should merge together without gaps, but not so much that the nozzle scrapes the bed or causes elephant foot. The layer should be smooth and even.
Adjust in steps of 0.02mm (20 microns). This is small enough to avoid over-correction but large enough to see a difference. Baby stepping during a print is the best way to dial it in.
Slightly. Different materials have different flow characteristics, so you may need a slightly different Z offset. Many users save per-material Z offset profiles.
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Last updated: February 2026
All calculations are estimates. Always verify settings with test prints before committing to final prints.