What is a good Flesch-Kincaid Reading Ease score?

Scores range from 0 to 100. 60–70 is considered plain English suitable for most adults. Scores above 70 are easy to read (think popular fiction or consumer websites); scores below 30 are very difficult (academic papers, legal contracts).

What does the Gunning Fog Index number mean?

The Fog Index estimates the U.S. grade level needed to understand the text. A score of 12 means a high-school senior reading level. Scores above 17 are considered academic or expert-level.

How is the SMOG Index calculated?

SMOG (Simple Measure of Gobbledygook) counts polysyllabic words (3+ syllables) in 30 sentences and applies a square-root formula. It is especially popular in healthcare communication and requires at least 30 sentences for reliable results.

Why do the four scores sometimes disagree?

Each formula weights factors differently. Flesch-Kincaid Reading Ease emphasizes syllables-per-word and words-per-sentence. Gunning Fog focuses on "complex" words (3+ syllables). SMOG uses a narrower polysyllabic count. Real-world texts rarely rank identically across all four.

How does the syllable counter work?

The tool uses a heuristic syllable estimator based on vowel groups, common English suffixes, and silent-e rules. It is accurate for most English prose but may slightly miscount unusual proper nouns or technical abbreviations.

How much text do I need for accurate results?

For the most reliable scores, use at least 100 words and 5 sentences. The SMOG Index specifically requires 30 sentences for its formula to be valid; the tool will warn you when the sample is too short.

Readability Score Checker

Paste any text to instantly get Flesch-Kincaid, Gunning Fog, and SMOG readability scores with grade-level explanations.

Paste Your Text

0 words 0 sentences

Paste text on the left to see readability scores

Summary

The Readability Score Checker analyzes your text using four established readability formulas: Flesch-Kincaid Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog Index, and SMOG Index. Each formula uses different combinations of sentence length, word length, and syllable counts to estimate the U.S. school grade level or ease of reading. This tool runs entirely in your browser — no text is sent to any server.

How it works

Paste or type your text into the input area.
The tool counts sentences, words, syllables, and complex words (3+ syllables).
Four readability formulas are applied to the same statistics simultaneously.
Each score is displayed with a plain-English interpretation and recommended audience.
Edit your text and the scores update automatically.

Use cases

Check whether blog posts or articles are accessible to your target audience.
Simplify legal, medical, or technical documents for general readers.
Verify that marketing copy meets readability guidelines for ad platforms.
Help students and academics calibrate writing complexity for assignments.
Audit e-learning content to match the reading level of learners.
Ensure government or compliance documents meet plain-language standards.
Compare readability before and after editing a draft.
Benchmark competitor content against your own writing.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu