3D Print Build Time Estimator

Most slicers and CAD tools report cross-sectional area readily, while path length per layer is rarely surfaced directly. The calculator derives an approximate path length by dividing the layer's area by a fixed 0.4mm extrusion width — the idea being that a wider bead covers more area per pass of the nozzle, so the same area requires proportionally less total path length to trace.

Travel time is approximated as 30% of the print path length at your travel speed, a rule-of-thumb ratio rather than a measurement of your specific geometry's actual nozzle repositioning moves. Parts with many small disconnected islands per layer will generate more real travel moves than this flat ratio assumes, so the estimate runs optimistic for highly fragmented cross-sections.

The model bakes in an average of two retraction/prime cycles per layer at your specified retraction time, standing in for the typical pattern of one retraction when finishing the outer perimeter and one when starting infill or moving between islands. Parts with many separate features per layer will retract more often than this average in practice, understating true print time slightly.

Because the calculator uses a single average cross-section for every layer, it works best for parts with roughly constant geometry from bottom to top. A tapered cone, a part with a wide base and narrow spire, or anything with dramatically different features at different heights will see the true print time diverge, since the top or bottom layers' actual area differs substantially from the average you entered.