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
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Last updated: February 2026
All calculations are estimates. Always verify settings with test prints before committing to final prints.