What is a good Flesch-Kincaid readability score?

For most web content, aim for a Flesch Reading Ease of 60–70 or a Flesch-Kincaid Grade Level of about 7–8, the ranges Microsoft recommends for most documents. Technical documentation often sits lower, around 50–60. Patient health information should be easier still: the AMA recommends a 6th-grade reading level and the NIH 8th grade.

What does a readability score of 60 mean?

On the Flesch Reading Ease scale, 60 is the bottom of the plain English band (60–70), which corresponds to an 8th–9th grade US reading level, text easily understood by 13- to 15-year-olds. Just below 60, text moves into the fairly difficult band, which maps to 10th–12th grade.

What is the difference between Flesch Reading Ease and Flesch-Kincaid Grade Level?

Both use average sentence length and average syllables per word, but weight them differently. Reading Ease, published by Rudolf Flesch in 1948, gives a 0–100 score where higher is easier. The Grade Level, derived for the US Navy by J. Peter Kincaid and colleagues in 1975, gives a US school grade where lower is easier.

How do I check Flesch-Kincaid grade level in Word?

In Word for Microsoft 365, open the Home tab, choose Editor, then Document stats. Word shows the Flesch Reading Ease and Flesch-Kincaid Grade Level for the document. Microsoft notes this is available to Microsoft 365 customers on the Current Channel. For a live web page, a URL-based readability checker is quicker than copying text into Word.

Is readability a Google ranking factor?

No. In a 2018 Webmaster Hangout, Google's John Mueller said that as far as he knew, Google doesn't use basic algorithms that count words to work out reading level. Readability still matters because visitors who can't follow a page leave, so write for your audience rather than for a number.

Flesch Kincaid Readability: What Score Should You Aim For?

The short answer

"Flesch-Kincaid readability" is really two formulas that share the same two inputs: average sentence length and average syllables per word. Flesch Reading Ease scores text from 0 to 100, where higher means easier. Flesch-Kincaid Grade Level turns the same inputs into a US school grade, where lower means easier. For general web copy, aim for a Reading Ease of about 60–70 (plain English, 8th–9th grade) or a grade level of about 7–8 — the ranges Microsoft's Word documentation recommends for most documents. Treat either number as a warning light, not a target: Google has said it doesn't use reading-level formulas like these to rank pages, and text can score well and still be hard to follow.

Two formulas, one pair of inputs

Rudolf Flesch, a plain-English advocate, published the Reading Ease formula in 1948 in the Journal of Applied Psychology, in a paper called "A new readability yardstick." In 1975, J. Peter Kincaid and colleagues recalculated it for the US Navy, along with the Automated Readability Index and the Fog Count, using test results from 531 enlisted personnel reading passages from Navy training manuals. That report produced the grade-level formula.

Flesch Reading Ease (0–100, higher = easier)
  206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words)

Flesch-Kincaid Grade Level (US school grade, lower = easier)
  0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59

Nothing else goes in. Longer sentences and longer words push Reading Ease down and Grade Level up. The weights differ, though: relative to Reading Ease, the grade formula leans more on sentence length and less on syllables, so one score can't be converted exactly into the other.

What does a Flesch Reading Ease score mean?

These are the standard interpretation bands, and the same cut-offs CheckSEO uses to label a page.

Reading Ease	US school level	What it means
90–100	5th grade	Very easy. An average 11-year-old can follow it.
80–90	6th grade	Easy. Conversational English.
70–80	7th grade	Fairly easy.
60–70	8th–9th grade	Plain English. Easily understood by 13- to 15-year-olds.
50–60	10th–12th grade	Fairly difficult.
30–50	College	Difficult.
10–30	College graduate	Very difficult. Best understood by university graduates.
0–10	Professional	Extremely difficult.

So a score of 60 sits right on the line between plain English and fairly difficult. The scale isn't truly capped, either: a passage made only of one-word, one-syllable sentences computes to 121.2, and enough long words can push a score below zero. CheckSEO clamps the Reading Ease it reports to 0–100.

How to calculate Flesch-Kincaid by hand

Count words, sentences and syllables, work out the two averages, then plug them in. Here are three sentences worked through:

Text:
  Readability formulas count two things.
  They measure how long your sentences are and how many syllables your words carry.
  Neither one can tell whether the writing makes sense.

Sentence 1:   5 words, 11 syllables   (read·a·bil·i·ty = 5, for·mu·las = 3)
Sentence 2:  14 words, 21 syllables   (sen·ten·ces = 3, syl·la·bles = 3)
Sentence 3:   9 words, 12 syllables   (nei·ther = 2, wheth·er = 2)
Total:       28 words, 44 syllables, 3 sentences

Words per sentence  = 28 ÷ 3  = 9.33
Syllables per word  = 44 ÷ 28 = 1.571

Reading Ease = 206.835 − (1.015 × 9.33) − (84.6 × 1.571)
             = 206.835 − 9.47 − 132.94
             = 64.4

Grade Level  = (0.39 × 9.33) + (11.8 × 1.571) − 15.59
             = 3.64 + 18.54 − 15.59
             = 6.6

The same passage scores 64.4 on Reading Ease (8th–9th grade) but 6.6 on the grade formula. That isn't a mistake, just the different weights at work, so pick one scale and track it rather than compare across them. Syllables are also where calculators drift apart. CheckSEO's syllable heuristic counts vowel groups after stripping endings such as a final -e or -es, so it reads "sentences" as two syllables instead of three. That one syllable lifts this passage's Reading Ease from 64.4 to 67.4.

Paste any URL into CheckSEO's free readability checker to see its Flesch Reading Ease, Flesch-Kincaid grade, average sentence length and syllables per word, plus the longest sentences on the page — no signup.

Check a page's reading level

What readability score should you aim for?

There is no universal target. The right number depends on who is reading:

General web copy and blog posts: Reading Ease 60–70 or grade 7–8, the ranges Microsoft recommends for most documents. CheckSEO flags anything under 60 for a general audience.
Technical documentation: 50–60 is a reasonable range for readers who expect precise terms. CheckSEO shows it as a warning rather than an error.
Patient health information: lower. The American Medical Association recommends a 6th-grade reading level and the National Institutes of Health 8th grade, according to a 2021 study in the Journal of Patient Experience. It found only 8.2% of 2,585 patient materials from high-impact medical journals met the NIH level.
Legal and insurance documents: sometimes set by law. Florida requires insurance policy forms to score at least 45 on Flesch Reading Ease (Florida Statutes § 627.4145), excluding items such as defined terms and medical terminology.
Children's content: match the reader's grade, and use the grade level rather than Reading Ease, which puts everything at 5th grade or below in the same 90–100 band. The grade formula can dip below zero for very simple text (its theoretical minimum is −3.4), which is why CheckSEO floors the grade it reports at 0.

Why the score isn't everything

A readability formula is a proxy built from two counts. That makes it fast and repeatable, and blind to most of what makes writing clear:

It ignores meaning. Shuffle the words inside every sentence and the score doesn't move.
It ignores word familiarity. Short, unfamiliar words like "tort," "writ" and "lien" count as easy. The same 2021 study notes that Flesch-Kincaid may underestimate the difficulty of text full of short but unfamiliar words.
It penalizes necessary jargon. A developer guide can't swap "idempotent" for a shorter word without losing meaning, and the formula charges for it anyway.
It ignores structure. The formulas have no concept of headings, lists or layout, which do much of the work of making a page scannable. Our guide to heading structure covers that side.
Choppy text scores well. A page of five-word sentences scores brilliantly and reads like a telegram.
Tools disagree. A 2022 study in JAMA Network Open ran the same health web pages through eight calculators and found scores varied by up to 12.9 grade levels, even with the same formula. Removing incomplete sentences and stray mid-sentence periods first narrowed the gap in most cases.

It isn't a ranking factor either. Asked about reading level in a 2018 Webmaster Hangout, Google's John Mueller said that as far as he knew, Google doesn't run basic algorithms that count words to work out reading level, but that it is "something that you should figure out for your audience." Yoast SEO has also moved on: since version 19.3 its readability analysis uses separate sentence-length and word-complexity checks instead of Flesch Reading Ease, which now sits in its Insights tab. Treat the score the way you'd treat keyword density: a quick sign that something may be off, not a number to hit.

How to raise your score without dumbing it down

Split long sentences at the joins

Look for "and," "but," "which" and semicolons in your longest sentences. Each is usually a point where one sentence can become two without losing meaning.

Swap long words only when a short one means the same

"Use" for "utilize," "about" for "approximately," "help" for "facilitate." Reading Ease multiplies syllables per word by 84.6, so cutting the average by just 0.05 adds about 4 points.

Keep necessary jargon and define it once

If readers need the term, keep it and explain it in plain words the first time it appears. The score barely changes; understanding does.

Cut filler phrases

"In order to" becomes "to," "due to the fact that" becomes "because," and "at this point in time" becomes "now." Fewer words, fewer syllables, nothing lost.

Vary the rhythm instead of chopping everything short

Mix short sentences with medium ones. A 20-word sentence that carries one idea is fine; readers struggle with sentences that carry three. CheckSEO flags sentences over 25 words and suggests keeping them under 15% of the total.

Check your own page

CheckSEO's Readability & Content Analyzer fetches any URL, isolates the main content (the <main> or <article> element, or the body with navigation, header and footer removed) and reports Flesch Reading Ease and Flesch-Kincaid grade using the standard formulas and a vowel-group syllable heuristic. It also shows word count, average sentence length, sentences over 25 words, reading time and text-to-HTML ratio. Flesch scores appear only when a page has at least 30 words across three or more sentences and at least half of its words are in Latin script, because the formulas were calibrated on English.

Flesch-Kincaid Readability Explained: What Score to Aim For (and Why It's Not Everything)