Finishing effort multiplies, it does not just add up
A large part with rough starting texture aiming for a show-quality finish is not simply "a bit more work" than a small part with fine layers aiming for light smoothing, it is disproportionately more work, because area, texture, and target all compound each other. Underestimating this is a common reason a finishing pass takes far longer than planned. This tool gives a rough effort band from those three factors together, so you can budget time realistically before starting.
How the estimate works
Surface area, starting layer texture, and finish target each contribute a score, and the combined total sorts into a low, moderate, or high effort band. A low band suggests a quick hand-sand is enough; a moderate band suggests a progressive sanding sequence with spot filling; a high band suggests a full fill-sand-prime cycle and explicitly flags that a coating or redesign alternative from the Surface Finish Route Selector is worth comparing against the labor cost.
Worked example
A medium surface area, visible layers, paint-ready target: the combined score lands in the moderate band, suggesting a progressive sanding sequence (150 to 600 grit) with filler primer on any visible gaps, a realistic middle-ground effort for this combination rather than either a quick pass or a full show-quality cycle.
A common mistake
A frequent error is jumping straight to a fine-grit sandpaper on a rough, freshly printed surface. Skipping the coarser grits in a progressive sequence takes far longer overall, since fine paper alone struggles to remove real layer-line height. Start coarser than feels necessary and work up through the grits; it is faster in total time than starting fine.
Limitations
This estimates an effort band from area, texture, and target as rough proxies, not a measured labor-hour prediction. Actual time depends heavily on your own technique and tools; use this as a planning signal, not a quote.