Free tool
How hard your writing is to read
This scores pasted text with the two standard Flesch formulas, then shows the two inputs that drive them: average sentence length and average syllables per word. It also flags your longest sentence, which is usually the fastest single fix. Syllable counting is algorithmic, so treat the grade level as a band.
Last reviewed 27 August 2026
Result
Flesch Reading Ease
63.9
Plain English. Eighth to ninth grade, the usual target for general business writing.
Flesch-Kincaid grade level
Grade 9.3
Your target is grade 10
The inputs behind both scores
| Measure | Value |
|---|---|
| Words | 80 |
| Sentences | 4 |
| Average words per sentence | 20.0 |
| Average syllables per word | 1.45 |
| Sentences over 30 words | 1 |
| Longest sentence | 48 words |
Longest sentence, in full
The sentences run long, the vocabulary is borrowed from the pitch deck, and the reader gives up somewhere in the second paragraph, which is a shame because the underlying argument is usually sound and would survive contact with a much plainer style if anyone bothered to apply one.
At grade 9.3 this sits inside your grade 10 target. Nothing structural to fix. Start with the 48 word sentence printed above. Cutting one sentence of that length in half usually moves the grade level more than a full pass of word substitutions.
How this works
What the numbers mean.
- 01Flesch Reading Ease is 206.835 minus 1.015 times average sentence length minus 84.6 times average syllables per word. Higher is easier. Both inputs are printed below the score so you can see which one is dragging.
- 02Flesch-Kincaid grade level is 0.39 times average sentence length plus 11.8 times average syllables per word minus 15.59. It converts the same two inputs into US school grades.
- 03Notice the weights. Reading Ease punishes long words far harder than long sentences, while the grade formula does the opposite. That is why the two scores can disagree about the same paragraph.
- 04The longest sentence is printed in full rather than summarised, because splitting one sixty word sentence usually moves both scores more than rewriting five short ones.
Assumptions and limits
- Syllables are counted by a vowel-group algorithm. It is close on ordinary English and wrong on names, acronyms, and unusual words, so the grade level is a band rather than a number.
- Sentence detection splits on periods, question marks, and exclamation marks. Abbreviations like Inc. and e.g. will split early and pull the average down.
- Both formulas were built for graded school texts, Reading Ease in 1948 and Flesch-Kincaid for US Navy training manuals in 1975. They travel reasonably to prose and badly to code, tables, and bullet lists.
- Neither formula reads your argument. A clear score on writing that says nothing is entirely possible, and common.
Questions about this tool
What is a good Flesch Reading Ease score?
Why do the two scores disagree?
Does a higher score mean better writing?
How accurate is the syllable count?
This tool is free and there is nothing to sign up for. If you would rather have the work done than calculate it, that is what Zway does.