FKGL

FKGL stands for Flesch–Kincaid Grade Level, a readability metric designed to estimate the US school grade level needed to understand a piece of English text. It is commonly used in education, publishing, and software to gauge text difficulty and tailor content to a target audience.

The FKGL is calculated from three counts of the text: words, sentences, and syllables. The standard formula is FKGL = 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59. Higher scores indicate more difficult text. In practice, the result represents the grade level at which a reader is expected to comprehend the material.

Historically, the Flesch–Kincaid readability tests were developed in the 1970s by Rudolf Flesch and J. Peter Kincaid to provide a simple, objective measure of readability. The Grade Level version is widely included in word processors and document editing tools, making it easy to estimate text difficulty during writing and editing.

Interpretation guidance suggests that lower FKGL values correspond to easier text, while values around 8–12 are typical for many general-audience materials. Text intended for broad public consumption often targets FKGL scores around the 8th to 9th grade.

Limitations include a focus on syntactic and lexical features rather than content quality or reader motivation, potential inaccuracies with unusual punctuation or abbreviations, and a language dependency restricted to English. It should be used alongside other measures when assessing text suitability for a given audience.