This page provides a song-wise scale reference for both SP and DP charts. Each table lists the chart title, difficulty label, discrimination, and the estimated EASY and HARD clear difficulty values.
Discrimination: how strongly a chart separates player skill levels.
Easy: estimated difficulty for achieving an EASY clear.
Hard: estimated difficulty for achieving a HARD clear.
These values are only rough analytical references, so please do not treat them as absolute or fully reliable ratings.