Readable Contracts Part 3

Readability, grade level, and sentence length

This is part 3 of a series discussing the study, “Poor Writing, Not Specialized Concepts, Drives Processing Difficulty in Legal Language,”[1] in which the authors compared contract language with everyday written English. I was able to contact the authors and access the corpora they used, and I conducted my own assessments. (Note: the corpus of contracts I used had 837,000 words; the corpus of everyday written English had more than a million words.)

I assessed the text for average sentence length, Flesch Reading Ease, and Flesch-Kincaid Grade Level, and also included those averages from my last 10 columns that have appeared here. The results:

These results support the conclusions of the original study’s authors, but I’ll say a bit more about them here.




Avg. Sentence Length

Flesch Reading Ease

Flesch- Kincaid Grade

Everyday written language

17 56 9

Contract language

42 20 19

Schiess’s last 10 columns

17 52 10

Average sentence length

The average for the everyday English—17 words—is short but typical: everyday-English sentences average 15 to 20 words. This corpus included blogs, web pages, and TV and movie scripts, so the low number makes sense.

The 42-word average for the contracts is, well, huge. As I pointed out last month, these are commercial contracts entered by sophisticated parties represented by counsel, so the long sentences aren’t as troubling as they might be if the contracts were apartment leases, credit-card agreements, or software-user agreements.

The 42-word average means that there are some really long sentences, and even experienced transactional lawyers might find reading those long sentences difficult.

Flesch Reading Ease

This formula, included in Microsoft Word, was finalized in 1948 by Rudolf Flesch, an Austrian lawyer who fled the Nazis in 1938 and earned a Ph.D. in education in the United States. It assesses the number of syllables and sentences per each 100 words and uses that assessment to produce a score from 0 to 100: 30 is difficult, and 60 is plain English.[2]

At 56, the everyday English text comes close to Flesch’s standard for plain English—as it should. And as we might have predicted, the Reading Ease score for the contract language is low—what Flesch labels “very difficult.”[3] The long average sentence length doubtless contributes to this low score, but the average number of syllables per word surely does, too.

Flesch-Kincaid Grade Level

This scoring system was derived from the Flesch Reading Ease score by J.P. Kincaid[4] and reports the number of years of formal education a reader needs in order to understand the text. The everyday English scored a 9, meaning one who has completed the ninth grade should be able to read and understand it. My own writing—which is mostly about writing—tends to hover around the tenth-grade level.

The Flesch-Kincaid grade level for the contract language is high at 19, although I once read a decision from an administrative-hearing appeal that scored a 20. But grade level 19 is, unsurprisingly, the equivalent of a reader with a high-school education (12), a college degree (16), and a law degree (19).

Thus, the grade level is appropriate given the context: these contracts were prepared by and for attorneys.


Still, the 42-word average sentence length is taxing at best and on the border of impenetrable. Anything we can do to reduce that average will make the contract easier to read and understand and, therefore, easier to draft, easier to review, and easier to explain to the client.

Next month: a report of additional findings based on the two corpora.


[1] Eric Martinez, Francis Mollica, & Edward Gibson, Poor Writing, Not Specialized Concepts, Drives Processing Difficulty in Legal Language, Cognition 224 (2022).

[2] William H. DuBay, Smart Language: Readers, Readability, and the Grading of Text 56 (2007); Rudolf Flesch, How to Write Plain English 25 (1979).

[3] Flesch, How to Write Plain English at 25.

[4] DuBay, Smart Language at 90-91.