Bridging Distance Calculator (Pre-Failure Check)
Predict if a bridge is likely to sag or fail before running a long print.
Bridge risk
61 / 100
Risk result
High risk61 / 100
- Predicted max bridge25.8 mm
- Requested / max ratio1.08x
- Estimated sag at span0.48 mm
Recommended actions
- Shorten bridge span by reorienting part or adding a support blocker only under the span midpoint.
FAQ
Can this replace bridge calibration prints?
It is a pre-check, not a replacement. Use it to avoid obviously risky spans, then verify with a quick bridge test for your exact printer and filament.
What helps bridges most for PLA and PETG?
Lower bridge flow, moderate bridge speed, and high fan on bridge layers usually give the biggest improvement.
Why does ABS still fail long bridges even with tuning?
ABS stays soft longer and benefits less from high fan, so long unsupported spans sag earlier than PLA under similar geometry.
Related tools & guides
Support Material Estimator
Estimate support grams before slicing when bridges are risky.
Warping Risk Predictor
Check thermal distortion risk for long unsupported spans.
Print Time Estimator
Estimate total job time before slicing.
Free 3D Print Cost Calculator
Full material, electricity, and margin cost breakdown.