What is ARI and why it matters for LinkedIn posts

I remember the first time someone told me my writing was "too complex." I thought they meant the ideas. They didn't. They meant the sentences were long, the words were heavy, and most people would bounce before finishing the second paragraph.

That feedback stuck with me, and it eventually led me to a metric called the Automated Readability Index, or ARI. If you write on LinkedIn and care about people actually reading what you post, this little formula is worth understanding.

The formula, explained simply

ARI looks at two things: how long your sentences are and how long your words are. That's it. The formula itself uses characters per word and words per sentence to produce a number that roughly maps to a U.S. school grade level.

A score of 6 means a sixth grader could read your text comfortably. A score of 14 means you're writing at a college level. The math behind it is straightforward: multiply the average word length (in characters) by about 4.71, add the average sentence length multiplied by 0.5, then subtract 21.43. You get a single number.

You don't need to memorize that. The point is that shorter words and shorter sentences push the score down, and longer ones push it up.

Why this matters on LinkedIn specifically

LinkedIn is not a journal. It's not an academic paper. It's a feed that people scroll through between meetings, on the bus, or while waiting for coffee. Your post is competing with hundreds of others for a few seconds of attention.

When your readability score is high (meaning the text is hard to read), people skip your post. They don't struggle through it. They just keep scrolling. It doesn't matter how brilliant your insight is if the packaging makes people's eyes glaze over.

There's also the international factor. LinkedIn's audience is global. A huge chunk of your readers are not native English speakers. Writing at a grade 12 level might feel natural to you, but it creates friction for a lot of your audience.

What score should you aim for?

For LinkedIn posts, I recommend aiming for an ARI between 6 and 8. That range is readable without feeling dumbed down. It's the sweet spot where your writing feels effortless to the reader, like a conversation rather than a lecture.

A score of 6 to 7 works great for broad audiences. If you're writing for a more technical crowd (say, software engineers or data scientists), you can push it toward 8 or 9, but going above 10 is almost always a sign that your sentences need breaking up or your words need simplifying.

For context, most bestselling non-fiction books sit around a 7. The most shared articles online tend to land between 6 and 8. There's a reason for that. Clear writing gets read. Complex writing gets abandoned.

How the editor helps

When I built the LinkedIn Content Studio, I wanted readability feedback to be instant. You paste or type your post, and the ARI score updates in real time. No need to copy your text into a separate tool or wait for an analysis report.

The score appears right next to your text as you write. If you see it climbing above 8, you know to look for long sentences you can split or fancy words you can swap for simpler ones. It turns readability from a vague goal into something concrete and actionable.

I've found that just having the number visible changes how you write. You start catching yourself mid-sentence, thinking "wait, that's getting long" and hitting a period instead of a comma. Over time, it trains you to write more clearly even without the tool.

A quick exercise

Take your last LinkedIn post and paste it into the editor. Look at the ARI score. If it's above 10, try rewriting just the first two sentences. Break long sentences in half. Replace any word over three syllables with a simpler alternative. Watch the score drop.

That's the whole game. Shorter sentences, shorter words, lower score, more readers. You don't have to sacrifice depth. You just have to respect your reader's time and attention.