Gunning Fog Index Calculator
Measure how complex your writing is with the Gunning Fog index.
Result
How to use
- Enter your values in the fields above.
- Press Calculate to see your result instantly.
- Use the Share button to copy a link to your result.
About this calculator
This calculator computes the Gunning Fog Index, a readability formula developed by Robert Gunning in 1952: Grade level = 0.4 × [(words / sentences) + 100 × (complex words / words)], where a complex word has three or more syllables (excluding common suffixes and compound words). The result approximates the years of formal education needed to understand the text on first reading.
Editors, technical writers, UX writers, and students use it to check whether a document, article, or set of instructions is written at an appropriately accessible level — a Fog Index above 12 is generally considered too complex for a general audience. Paste your text to get the Fog Index and estimated grade level.
Was this helpful?
Popular calculators
Loan Calculator
Monthly payment, total interest and full amortization schedule.
Percentage Calculator
Percent change, percent of, and ratio calculations.
Discount Calculator
Calculate final price, savings, and discount amount.
BMI Calculator
Body mass index from height and weight (metric or imperial).
Age Calculator
Compute your exact age in years, months and days from a birth date.
Compound Interest Calculator
Calculate the final amount and interest earned with compounding.
All Calculators
No calculators found
Comments (0)