Six formulas, one text
Paste your text and the checker scores it with the six formulas most often used in English. Each one combines two measures: how long your sentences are, and how long your words are.
| Score | Measures | Read it as |
|---|---|---|
| Flesch Reading Ease | words per sentence, syllables per word | 0–100+; higher is easier. 60–70 is plain English |
| Flesch–Kincaid Grade | words per sentence, syllables per word | US school grade |
| Gunning Fog | words per sentence, share of words with 3+ syllables | years of schooling |
| SMOG | words with 3+ syllables per 30 sentences | grade needed for full understanding |
| Coleman–Liau | letters per 100 words, sentences per 100 words | US school grade |
| Automated Readability Index | characters per word, words per sentence | US school grade |
The average grade is the mean of the five grade-level scores. When they disagree a lot, it usually means your text has an unusual mix: short sentences full of long words, or long sentences of short ones.
Below the scores you will find the counts each formula used and your hardest sentences, ranked by Flesch–Kincaid grade. Click a sentence to select it in the text. Long sentences are highlighted in the text box: yellow at 25 words, darker at 35.
How the numbers are made
Three of the formulas need syllables. Counting syllables by spelling is harder than it sounds (“fire”, “every”, “created”), and every tool does it a little differently. That alone explains most of the gap between checkers. Ours combines spelling rules with an exception list of 462 frequent words taken from the CMU Pronouncing Dictionary. On a hand-checked list of 354 words it gets 97.7% right. The methodology page lists every test, including the words it still misses.
The formulas reproduce their published worked examples. For the Gettysburg Address our Flesch–Kincaid grade is 10.96, against 10.9 published by the University of South Florida’s Lit2Go collection.
Using the result
A readability score is a smoke alarm, not a verdict. It tells you that your sentences or words are long. It cannot tell you whether the reader knows your terms, whether your points come in a sensible order, or whether a long word is the right one. Use the score to find the passages that need work, then read those passages aloud.
To raise Reading Ease or lower the grade:
- Split the longest sentences first. They move every formula the most. See how to write shorter sentences.
- Swap long words for short ones where the meaning holds: “use” for “utilize”, “help” for “facilitate”. The plain words list has hundreds of pairs.
- Turn nominalizations back into verbs: “decide” for “make a decision”. See nominalizations.
What score should I aim for?
It depends on your readers. For the general public, plain-language practice often aims at about grade 8 or lower, a Reading Ease of 60 or more. Specialist readers can take more. The guide What readability score to aim for explains why chasing a number can backfire.
Why is SMOG marked as rough?
SMOG was built for samples of 30 sentences. With fewer, the formula scales up what it found, so a single long word moves the score a lot.
Does it work for other languages?
No. All six formulas were built for English. Chinese and Japanese characters are counted as words but left out of the scores.