What is the 45-degree rule?

The general rule of thumb is that FDM printers can handle overhangs up to 45 degrees from vertical without supports. At 45 degrees, each layer is offset by exactly one layer height from the layer below, giving roughly 50% overlap.

How does cooling affect overhang ability?

Better cooling solidifies each layer faster before the next layer is deposited, reducing drooping. PLA with 100% fan can often achieve 55-60 degree overhangs. Materials like ABS that need minimal cooling struggle beyond 40 degrees.

Does layer height affect overhang quality?

Yes. Thinner layers produce better overhangs because each layer overhangs by a smaller distance (less droop). At 0.1mm layers you can often achieve 5-10 degrees more overhang than at 0.3mm layers.

What is the difference between overhang angle and draft angle?

Overhang angle is measured from vertical (0 = vertical wall, 90 = horizontal ceiling). Draft angle is measured from horizontal. They are complementary: a 45-degree overhang equals a 45-degree draft. Some slicers use one convention, some the other.

3DPrintCalcs

Overhang Calculator — Maximum Angle Without Supports

Calculate the maximum overhang angle and distance your printer can handle without supports.

Layer Height

Line Width

Your Overhang Angle

From vertical (0=wall, 90=ceiling)

Cooling Fan

Material

How We Calculate This

Overhang Calculation

Max safe angle = Material base angle + Cooling bonus + Layer ratio factor
Overhang distance = Layer height / tan(Angle)
Layer overlap = (Line width - Overhang distance) / Line width x 100

Each layer overhangs the previous one by an amount determined by the angle and layer height. As long as there is sufficient overlap with the layer below (typically more than 40%), the overhang prints without support.

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.