Overhang Angle Calculator — Support Requirements

This calculator works out the steepest overhang that prints cleanly without supports, then compares it to your angle. The starting point is geometry, with material and cooling applied as realistic corrections.

Geometric safe angle

A wall leaning θ from vertical advances layer height × tan(θ) sideways each layer. The new line stays bonded while that advance leaves enough overlap with the line below, which gives the overlap-limited ceiling:

Max angle = arctan( line width × (1 − overlap) ÷ layer height )

With a 0.4 mm line, 0.2 mm layer and 33% minimum overlap this is arctan(0.4 × 0.67 ÷ 0.2) = arctan(1.34) ≈ 53°. Wider lines and thinner layers raise the ceiling; taller layers lower it.

Material and cooling correction

PLA cools fast enough to reach the geometric ceiling; PETG, ABS, TPU and Nylon set more slowly and fall a little short, and weak part cooling drops the achievable angle further. The safe angle is the geometric ceiling scaled by these factors. Resin (SLA/DLP) cures each layer fully, so overlap is not the limit and any angle is supported.

Overhang distance per layer

Distance = Layer height × tan(angle) — at 45° a layer advances exactly one layer height.

Angles are measured from vertical: 0° is straight up (no overhang), 45° is the classic rule-of-thumb, 90° is fully horizontal (a bridge).