Boost readability with the Flesch Reading Ease Index

The higher your score, the easier your message is to read

In 1946, lawyer, author and writing consultant Rudolph Flesch “started a revolution in journalism and business communication.” That’s when Flesch published a readability formula in his dissertation, “Marks of a Readable Style.”

Boost readability with the Flesch Reading Ease Index — **Hit the right target** What readability scores to aim for on three top readability tests. *Image by Creativa Images*

That formula, the Flesch Reading Ease index, was the original Flesch test. The formula is:

206.835 – (1.015 x words per sentence)

– (84.6 x syllables per word)

= reading ease

(It might seem weird that a lawyer would support readability. But lawyers like to win, and to win, they need to write understandable arguments. Flesch is not the only lawyer to lead readability efforts. In 1979, for instance, attorney Robert Charrow worked with linguist Veda Charrow to improve readability in jury instructions. More recently, Joseph Kimble has chronicled case studies of organizations that have boosted ROI by improving readability.)

Flesch’s work with the Associated Press helped bring the reading level of front-page newspaper stories down by five grade levels. Publishers increased readership by 40% to 60% with the formula. Today, the Flesch test is one of the most widely used, most tested and most reliable readability formulas. U.S. Department of Defense, government agencies and Florida use this Flesch test.

Scores range from 0 to 100. The higher the score, the easier your message is to read.

Flesch Reading Ease
Score	Level	Words/ sentence	Syllables/ word	Estimated school grade completed	% of adults who can read at this level
90-100	Very easy	8 or fewer	1.23 or fewer	4th	93
80-90	Easy	11	1.31	5th	91
70-80	Fairly easy	14	1.39	6th	88
60-70	Standard	17	1.47	7th or 8th	83
50-60	Fairly hard	21	1.55	Some high school	54
30-50	Hard	25	1.67	High school or some college	33
0-30	Very hard	29 or more	1.92 or more	College	4.5

Target: Aim for 60 or higher. To increase your score, reduce the length of your sentences and words.

How long should your message be?

Would your message be twice as good if it were half as long?

Yes, the research says. The shorter your message, the more likely readers are to read it, understand it and make good decisions based on it.

So how long is too long? What’s the right length for your piece? Your paragraphs? Your sentences? Your words?

Find out at Rev Up Readability — our clear-writing workshop, which starts June 20.

There, you’ll use a cool (free!) tool to analyze your message for 27 readability metrics. You’ll leave with quantifiable targets, tips and techniques for measurably boosting readability.

Save up to $100 with our group discounts.