Lensear Write Readability Formula

The Lensear Write Readability Formula is a simple measure that was designed for English language text. It was developed for people who were in the U.S. Airforce. It helped them calculate the readability of their difficult-to-read high-tech manuals.

But first, what is a readability index?

A readability index estimates how difficult you find reading a text. To get an estimation, you would have to measure how difficult the text is to read. Measurable attributes of texts would be word length, sentence length, and syllable counting.

The Lensear Write is part of other readability metrics

The Lensear Write was particularly designed to work out what the U.S. grade level of any given text was using a simple measure. Its estimates are based on the length of the sentences as well as the number of words used – particularly words that consist of more than three syllables.

If you know the names of other reading indexes and formulas, you will know that the Lensear Write is similar to the Fry Readability Formula.

Making sense of the Lensear

The standard Lensear Write metric, like many other readability indexes, uses a 100-word sample. You add points to the different required features.

For instance, you add 1 point for easy words. The easy words have less than two syllables in them. For the hard words, which consist of more than three syllables, you add 3 points. Then you divide the points you have by the number of sentences found in the 100-word sample.

The result would give you the reading grade level of the text. That would relate to the number of years of education you need to understand and read the text fluently.

Readability metrics go back in time

The idea behind readability metrics like the Lensear Write metric goes back to the days of 1966. A government employee called John O'Hayre wrote a manual called Gobbledygook Has Gotta Go.

In his manual, John O’Hayre suggested a metric where shorter sentences and shorter, easier words would make it easier for people to read and build reading skills. By using a 100-word sample, the easy words that had just one syllable in them would earn one point. The sentence length would be worth three points.

At some point in time, the entire Lensear Write Index was created. He argued that simple communication was more efficient. O’Hayre recognized the value of clarity. He found it was more efficient for not only the public but also for internal communication.

Inspired by the use of easy, plain language

When O’Hayre wrote his manual, he warned people against using ‘official’ terms, like all that jargon and confusing terms that you so often see but that so many people don’t understand. He pointed out that many manuals use jargon just to make things sound official and important.

He encouraged those writing manuals and technical documents to fit the writing style to the age of the person to who the manual was aimed. He wanted to bring the writing style closer to the way people speak to each other, using simpler terms and a more natural tone.

Can you benefit from using the Lensear Write Formula?

The style of writing is important in the assessment items of the Lensear Write Formula. You get points for using words like “is” or “the” or “are” or “were,” for instance. You are encouraged to rather choose stronger verbs and avoid passive phrases.

In his manual, O’Hayre talks about the scientist Einstein. You'd imagine his academic literature would be full of complicated ideas. And yet Einstein made an effort to write metaphors about his scientific theories. He wanted average readers to understand scientific knowledge and would write in layman's terms to accomplish this.

If Einstein was able to simplify his writing and make it more engaging for everyone to read and understand at their level of education, then you can too. When you are giving points to the paragraphs, remember to try and aim for a score between 70 and 80.

Using the Lensear to grade your text

You can use the free Lensear Write Readability Calculator to grade your text. Here is how you calculate the grade level of a text using this readability assessment:

  1. Use a sample of 100 words to test.
  2. Calculate the easy words that have two syllables or less. Place the number "1" over each word, even the easy words like ‘a,’ ‘an,’ or ‘the’, for instance.
  3. Now calculate the hard words. These will have three syllables or more in them. Place a number "3" over each word.
  4. Multiply the number of easy words times "1." Then multiply the number of hard words by "3."
  5. Then add the two previous numbers together.
  6. Divide the total you get by the number of sentences.
  7. If your answer is >20, then divide by "2," and that is your result. If your answer is <20 or equal to 20, subtract "2," and then divide by "2" for your result.

Remember that average sentence length and words with more than three syllables will influence the results of the Lensear Write formula scores. Using shorter sentences and less complex words will lower your grade level score.

The readability index is essential for SEO

Most texts you find on the internet should provide information quickly and clearly. That means readability is essential.

SEO experts show that texts with readability scores of between 30 and 60 are the best. It is assumed that readability influences search engine rankings. Therefore it is advised that people use a readability index as part of search engine optimization and check the text content accordingly.


It doesn’t matter whether you are a blogger, a marketer, or an online editor. Any person who writes online texts should use the simple strategies discussed above to ensure their content is easy to read and understand so that they can help to achieve good rankings in search engine results.

For SEO purposes, keywords, headlines, links, and images are top-ranking factors. SEO analysts have found that texts with good readability generally rank better. You can see why readability is important and why the Lensear Write Formula is a valuable method for the improvement of readability. 

All Readability Tests:

Here is a list of all readability tests.

Jonathan Gillham

Founder / CEO of I have been involved in the SEO and Content Marketing world for over a decade. My career started with a portfolio of content sites, recently I sold 2 content marketing agencies and I am the Co-Founder of, the leading place to buy and sell content websites. Through these experiences I understand what web publishers need when it comes to verifying content is original. I am not For or Against AI content, I think it has a place in everyones content strategy. However, I believe you as the publisher should be the one making the decision on when to use AI content. Our Originality checking tool has been built with serious web publishers in mind!

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