Readability Score Calculator (Flesch, Gunning Fog, SMOG)
How readable is your text? Four widely-used scoring formulas give different angles: Flesch Reading Ease (0-100, higher = easier), Flesch-Kincaid Grade (US school grade), Gunning Fog (years of education), SMOG Index (used for medical/govt content), Coleman-Liau Index (character-based, no syllable counting).
How to use the Readability Score Calculator (Flesch, Gunning Fog, SMOG)
Paste text. Output shows scores from 4 formulas plus an interpretation. For wide audience use Flesch Reading Ease > 60 (8th grade or simpler).
Measuring how hard text is to read
Readability formulas turn sentence length and word complexity into a single number that estimates how much education a reader needs to follow your text. Newsrooms targeting a wide audience use them, government and medical writers held to plain-language standards rely on them, and they help anyone aiming for prose that does not tax the reader.
This scores your text with five established formulas — Flesch Reading Ease, Flesch-Kincaid Grade, Gunning Fog, SMOG, and Coleman-Liau — and interprets the results, since each weighs syllables, words, and sentences differently. For raw counts and reading time alongside the grade, pair it with Word Counter Pro.
Common use cases
- Content editing — check an article hits a target reading level.
- Plain-language compliance — meet a grade-level rule for public-facing text.
- Medical and legal writing — use SMOG, which was designed for health materials.
- Audience targeting — aim for Flesch Reading Ease above 60 for a general audience.
- Comparing drafts — see whether an edit made the text easier or harder.