A conformable sanding block with a longitudinal axis has a locking end cap, a sliding end cap and a series of indexable segments therebetween. A flexible position rod is fastened to both end caps and passes through and captures each indexable segments forming the ergonomically conformable sanding block that is settable between concave and convex shapes for sanding contoured shapes. The sanding block has a bottom whereat a sandpaper holder is releasably and slidably attached for releaseably fastening sandpaper thereto.