How to Check the Reading Level of Your Text — and Why It Matters More If You Used AI to Write It

Picture this: you hand over a client report, a grant proposal, or a product page you drafted with help from an AI tool. The content is accurate. It looks clean. But the feedback comes back — "This is too dense for our audience." Or the opposite: "This reads like it was written for teenagers."

The information isn't wrong. The reading level is.

And if you've been writing with AI tools, this problem is more common than most people realize — because AI tends to produce text at a consistent register regardless of who's actually going to read it.

What Is Reading Level, Exactly?

Reading level measures how easy or difficult a piece of text is to understand. Most formulas estimate the grade level of education a reader would need to follow the text comfortably. A Flesch-Kincaid Grade Level of 8 means an average 8th grader could read it without struggle. A score of 14 puts you firmly in post-secondary territory.

The most widely used formulas:

• Flesch-Kincaid Grade Level — the standard in academic and professional settings; outputs a US grade level based on sentence length and syllable count
• Flesch Reading Ease — a 0–100 scale where higher means easier; plain English typically scores in the 60–70 range
• Gunning Fog Index — estimates years of formal education needed to understand the text
• SMOG Index — widely used in healthcare for patient-facing materials
• Coleman-Liau Index — uses character counts instead of syllable counts, which makes it reliable for automated tools

They don't always agree — and that's fine. Different formulas catch different things. Using more than one gives you a fuller picture of where your text actually lands.

How to Determine the Reading Level of Any Text

The fastest way is to paste your text into a dedicated readability tool. WriteMask's readability checker gives you multiple scores simultaneously — Flesch-Kincaid, Reading Ease, and more — in seconds, for free.

The basic workflow:

• Paste your text into the tool
• Note the grade level score and the reading ease score
• Compare against the target level for your specific audience
• Edit sentence length, word choice, or clause structure as needed
• Re-check until the score lands in the right range

The two biggest levers are sentence length and word complexity. Shorter sentences drop the grade level fast. Swapping polysyllabic words for simpler synonyms does the same. To raise the level, you reverse that — longer sentences, more technical vocabulary. It's mechanical once you see it.

What Reading Level Should Your Text Actually Be At?

It depends entirely on your audience — and many writers skip this step entirely, which is where the mismatch starts.

• General public content (blogs, website copy, consumer-facing pages): aim for grade 6–8
• Healthcare or patient materials: grade 6 or below is the target in many health systems, and in some jurisdictions it's a regulatory expectation
• Business or professional writing: grade 10–12 is normal; above 14 and you risk losing even engaged readers
• Academic writing: grade 12–16 is expected, though it varies significantly by discipline

If your content is public-facing and you're unsure where to aim, grade 8 is a widely-used benchmark. The plain English movement in government, law, and healthcare specifically targets this range for accessibility.

Why AI Writing Makes This Problem Harder to Spot

AI language models tend to produce text that clusters at a predictable grade level — often in the 10–13 range — regardless of your prompt. That's because they're trained on a large volume of text that skews toward formal writing styles. The result is content that feels professional but may be subtly mismatched to your actual reader.

This is also one of the patterns that AI detectors pick up on: uniform sentence length and consistent vocabulary complexity across a document, without the natural variation a human writer introduces. The same quality that misses your audience can also raise a flag in detection tools. If you've ever been puzzled by a false positive on AI detection, reading level uniformity is one of the less-obvious reasons it happens.

If you're using AI to draft content for a specific reader — students, patients, customers, a niche professional audience — a reading level check isn't optional. It's the difference between content that lands and content that bounces.

How to Fix It Once You've Found the Problem

If your AI-drafted text is scoring too high for your audience, WriteMask is built exactly for this situation. It adjusts the language to sound more natural and human — which also tends to bring reading level down into a more accessible range, because it introduces the sentence-length variation and vocabulary shifts that formal AI output lacks. WriteMask carries a 93% pass rate on AI detection, and much of that comes from the same naturalness that makes text easier to read.

A clean two-step workflow: run your draft through WriteMask first to humanize the register, then use the readability checker to confirm the grade level landed where you need it. Readability and naturalness tend to improve together.

If you're also thinking about your search performance, it's worth knowing that Google's approach to AI content increasingly rewards reader experience — and matching your reading level to your audience is a direct input to that. Readers who can actually follow your text stay longer. That signal matters.