Readability Curve: Flesch-Kincaid Score & Grade Level (2D)

This 2D companion plots the same Flesch Reading Ease and Flesch-Kincaid Grade Level formulas as a direct retention curve instead of a rotatable 3D crowd of walking readers: the x-axis is reader literacy grade, the y-axis is the modelled fraction of readers at that grade who can follow your text, and a vertical line marks the text's own effective grade (base grade plus a jargon-density penalty). Push sentence length, syllable count and jargon up and watch the curve — and the effective-grade line — shift right, shrinking the share of any given audience that clears the bar; drag the audience-literacy slider to move the marker along the curve and read off retention for a general-public crowd versus a specialist one.