Reading Level Calculator
Paste any text to calculate its Flesch-Kincaid grade level and reading ease score.
Find out what grade level your writing targets.
Reading level measures how difficult a text is, based on sentence length, word complexity, and syllable count. Several standardized formulas are used in education, publishing, and content creation.
Flesch-Kincaid Grade Level Formula:
FK Grade = 0.39 × (words/sentences) + 11.8 × (syllables/words) − 15.59
Flesch Reading Ease Formula:
Reading Ease = 206.835 − 1.015 × (words/sentences) − 84.6 × (syllables/words)
Score interpretation:
- 90–100: Very easy (5th grade)
- 70–80: Easy (7th grade)
- 60–70: Standard (8th–9th grade)
- 30–50: Difficult (college level)
- 0–30: Very difficult (professional/academic)
Gunning Fog Index:
Fog Index = 0.4 × (words/sentences + 100 × complex_words/words)
Complex words = words with 3+ syllables (excluding proper nouns and compound words)
Worked Example:
A sample paragraph: 100 words, 5 sentences, 140 syllables, 10 complex words.
Average sentence length = 100 / 5 = 20 words Average syllables per word = 140 / 100 = 1.40
FK Grade = 0.39 × 20 + 11.8 × 1.40 − 15.59 = 7.8 + 16.52 − 15.59 = 8.71 (9th grade)
Fog Index = 0.4 × (20 + 100 × 10/100) = 0.4 × (20 + 10) = 12.0 (high school senior)
Reading Level Targets by Content Type:
| Content | Target Grade Level |
|---|---|
| Children’s books | 2–5 |
| Newspapers | 6–8 |
| General web content | 7–8 |
| Business writing | 8–10 |
| Legal / academic | 12–16 |
Practical Tips:
- Shorter sentences and common words always lower the reading level
- Tools like Hemingway Editor calculate these scores automatically
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.