Fleisch-Kinkaid and Readability Ease

One of the more interesting things I've picked up over the last year is the formulas used to score readability of writing. The Fleisch-Kinkaid Reading Age (FKRA) scale is used to determine what age group your work is best suited for, and the Readability Ease (RE) scale is used to determine how easy or confusing the work is.

Both scales use at least a paragraph (the more the better) of text, and two values must be calculated:

• ASL: This is the Average Sentence Length. In order to calculate this, you count the number of sentences in your paragraph(s). Then you count the number of words in the paragraph(s). Finally, you divide the number of words by the number of sentences.
• ASW: This is the Average Syllables per Word. This number is derived by dividing the number of syllables in your paragraph(s) by the number of words.

The FKRA scale formula is:

FKRA = .39ASL + 11.8ASW - 15.59

This will give you the grade level (1-12 primary and secondary school, and then 14-21 for college). If you add 5 years to this number, you will get the age level.

The RE scale formula is:

RE = 206.835 - 1.015ASL - 84.6ASW

This will return a score of 0-100, where 0 is very confusing and 100 is very easy.

I will illustrate with two examples. First a selection from the currently popular (though I'm not sure why) "50 Shades of Gray"by E.L. James:

His office is way too big for just one man. In front of the floor-to-ceiling windows, there's a huge modern dark-wood desk that six people could comfortably eat around. It matches the coffee table by the couch. Everything else is white -- ceiling, floors, and walls except, on the wall by the door, where a mosaic of small paintings hang, thirty-six of them arranged in a square. They are exquisite -- a series of mundane, forgotten objects painted in such precise detail they look like photographs. Displayed together, they are breathtaking.

There are 6 sentences, 92 words, 122 syllables. That means an ASL of 15.3 and an ASW of 1.3. Our FKRA is therefore 5.717, or almost a 6th-grade reading level (10- to 11-year-olds). The RE is 81.325, or a fairly easy read. In other words, for the target audience (adults), this book is quite juvenile in its writing style. Let's compare that to a paragraph from "The Element" by Ken Robinson:

From that moment of epiphany, Ewa knew that she wanted to dedicate her life to billiards. Fortunately, her parents supported her, allowing her to spend six to ten hours a day playing at a local poolroom, doing her homework in between shots. "People there knew I was serious about the game, so they left me alone. But we also had a lot of fun there. If you find a place where everybody else likes the same thing that you do, it really becomes fun. So these odd characters -- because we all had billiards together -- we became like a family."

Here there are also 6 sentences, with 101 words and 144 syllables; giving an ASL of 16.9 and an ASW of 1.4. That gives an FKRA of 7.5 (half-way through 7th grade, or 12-year-olds). The RE is 71.241, or a decent level of ease. This paragraph is just slightly lower on scale for the adults it is targeted to.

There are sites, of course, which will calculate all of these values for you, such as Readability-Score.com. But it is always handy to know this information for yourself!