How to use it
- Paste English text of at least a few sentences. All scores update as you type.
- Read the Flesch Reading Ease score first, then the grade levels.
- Shorten long sentences and replace words of three or more syllables to bring the scores down, and check again.
How it works
The tool counts words, sentences, letters and syllables. A syllable is a group of vowels, after a silent final “e”, “es” or “ed” is ignored, and words of three letters or fewer count as one. Words with three or more syllables are “complex”. With W words, S sentences, Y syllables, C complex words and L letters:
- Flesch Reading Ease = 206.835 − 1.015 × (W/S) − 84.6 × (Y/W)
- Flesch-Kincaid grade = 0.39 × (W/S) + 11.8 × (Y/W) − 15.59
- Gunning Fog = 0.4 × (W/S + 100 × C/W)
- SMOG = 1.043 × √(30 × C/S) + 3.1291, scaled from the 30-sentence sample it was made for
- Coleman-Liau = 0.0588 × (100 × L/W) − 0.296 × (100 × S/W) − 15.8
- ARI = 4.71 × (L/W) + 0.5 × (W/S) − 21.43
Worked example
“The cat sat on the mat.” has 6 words, 1 sentence and 6 syllables. Flesch Reading Ease is 206.835 − 6.09 − 84.6 = 116.1, and the Flesch-Kincaid grade is 2.34 + 11.8 − 15.59 = −1.5, so the text is extremely easy. A negative grade just means simpler than the first grade.
Tips
Do not chase one number. Very short sentences can score as “easy” and still read badly. Names, numbers, abbreviations and lists distort the counts, so remove them before scoring if you want a cleaner comparison.